drawio

name: drawio description: Visual style guide and workflow for creating Cisco network topology diagrams in Draw.io. Use when generating a topology diagram, creating or updating a topology.drawio file, or when any other skill needs to produce or validate a network diagram.

Draw.io Diagram Skill

-# Instructions

--# 1. Locations

Store diagrams in the following directories based on their type:

• Topology Diagrams: labs/<topic>/lab-NN-<slug>/topology/topology.drawio
  • Use for network topologies, physical cabling, and logical connectivity.
  • The diagram lives inside the topology/ subdirectory alongside topology/README.md.
• Flow Diagrams: labs/<topic>/lab-NN-<slug>/flow-[description].drawio
  • Use for packet flows, process charts, and logic flows.

--# 2. File Formats & Deliverables

The only required deliverable is:

1. Source File (.drawio): The editable XML format. This is the canonical diagram file.

--# 3. Naming Conventions

• Use kebab-case for all filenames.
• Pattern: [lab-name]-[diagram-type].extension
• Examples:
  • eigrp-basic-adjacency-topology.drawio
  • packet-flow-vlan-routing.drawio

--# 4. Visual Style Guide

This section defines the canonical visual style for all topology diagrams. Every generated .drawio file must follow these rules.

Reference file: references/style-guide-reference.drawio — a complete, validated example diagram. Read it when generating a new diagram to confirm style compliance before producing output.

4.1 Canvas & Layout

• Background: #1a1a2e (dark navy). Set in the <mxGraphModel background="#1a1a2e"> attribute of the XML root element.
• Title: Positioned at the top center of the canvas. Bold, 16pt, white text. Wrapped in a rounded frame with a white border and no fill (strokeColor=default;fillColor=none;rounded=1;) — the framing visually anchors the title against the dark canvas. Do NOT use strokeColor=none.
• Legend Box: Required in every diagram. Positioned at the bottom-right corner. Black fill (#000000) with white text (#FFFFFF), rounded corners, 10pt font.

4.2 Device Icons

• Use the Cisco19 shape library (mxgraph.cisco19). Do NOT use the older mxgraph.cisco library.

• All devices: width="60" height="60" (use width="50" height="40" for end hosts/workstations).

• Style Strings (include sketch=0;html=1;aspect=fixed;pointerEvents=1; on every icon):

  • Router:

    sketch=0;points=[[0.5,0,0],[1,0.5,0],[0.5,1,0],[0,0.5,0],[0.145,0.145,0],[0.8555,0.145,0],[0.855,0.8555,0],[0.145,0.855,0]];html=1;aspect=fixed;pointerEvents=1;shape=mxgraph.cisco19.rect;prIcon=router;fillColor=#FAFAFA;strokeColor=#005073;
    

  • L3 Switch:

    sketch=0;points=[[0.015,0.015,0],[0.985,0.015,0],[0.985,0.985,0],[0.015,0.985,0],[0.25,0,0],[0.5,0,0],[0.75,0,0],[1,0.25,0],[1,0.5,0],[1,0.75,0],[0.75,1,0],[0.5,1,0],[0.25,1,0],[0,0.75,0],[0,0.5,0],[0,0.25,0]];html=1;aspect=fixed;pointerEvents=1;shape=mxgraph.cisco19.rect;prIcon=l3_switch;fillColor=#FAFAFA;strokeColor=#005073;
    

  • L2 Switch:

    sketch=0;points=[[0.015,0.015,0],[0.985,0.015,0],[0.985,0.985,0],[0.015,0.985,0],[0.25,0,0],[0.5,0,0],[0.75,0,0],[1,0.25,0],[1,0.5,0],[1,0.75,0],[0.75,1,0],[0.5,1,0],[0.25,1,0],[0,0.75,0],[0,0.5,0],[0,0.25,0]];html=1;aspect=fixed;pointerEvents=1;shape=mxgraph.cisco19.rect;prIcon=workgroup_switch;fillColor=#FAFAFA;strokeColor=#005073;
    

  • Cloud/Internet:

    sketch=0;points=[[0,0.64,0],[0.2,0.15,0],[0.4,0.01,0],[0.79,0.25,0],[1,0.65,0],[0.8,0.86,0],[0.41,1,0],[0.16,0.86,0]];html=1;aspect=fixed;pointerEvents=1;shape=mxgraph.cisco19.cloud;fillColor=#6B6B6B;strokeColor=none;
    

  • Workstation/PC/VPC:

    sketch=0;points=[[0.03,0.03,0],[0.5,0,0],[0.97,0.03,0],[1,0.4,0],[0.97,0.745,0],[0.5,1,0],[0.03,0.745,0],[0,0.4,0]];html=1;aspect=fixed;pointerEvents=1;shape=mxgraph.cisco19.workstation;fillColor=#005073;strokeColor=none;
    

4.3 Device Labels

Labels are embedded in the device cell value as HTML — NOT as separate text cells.

• Format: <b style="color:#FFFFFF;">HOSTNAME</b><br><font color="#CCCCCC" style="font-size:10px;">ROLE<br>Lo0: IP/MASK</font>
• Hostname: white bold text.
• Role and Loopback: #CCCCCC gray, 10px.

Label position is controlled by adding these attributes to the device's style string:

4.3.1 Smart Label Placement — Empty Side Rule

Labels must not overlap any connection lines. Choose the placement based on which side has no connections:

Examples from EIGRP Lab 08:

• R2 is at x=500. All neighbors (R1 at x=400, R3 at x=400) are to the LEFT → label goes RIGHT (labelPosition=right).
• R6 is at x=200. Its neighbor R1 is at x=400, which is to the RIGHT → label goes LEFT (labelPosition=left).

4.4 Connection Lines

• Color: White (#FFFFFF). Never black.
• Style String: endArrow=none;html=1;strokeWidth=2;strokeColor=#FFFFFF;fillColor=#f5f5f5;
• Dashed Links (tunnels): endArrow=none;html=1;strokeWidth=2;strokeColor=#FFFFFF;fillColor=#f5f5f5;dashed=1;
• Edge Labels (interface names + subnet): Centered on the link. 10pt. Include interface pair and subnet on separate lines.
  • Example value: Fa1/0 - Fa0/0\n10.12.0.0/30

4.5 IP Last Octet Labels

• Required: Every router interface endpoint must have a small label showing the last octet of its IP address (e.g., .1, .2).
• Bind octet labels to the link (NOT to canvas coordinates). This is mandatory: the octet must follow the link when nodes are repositioned. Octets parented to "1" (canvas root) at absolute X/Y must be repositioned by hand every time a node moves — that is the wrong pattern and is forbidden.
• Parenting: Set the octet cell's parent to the link cell's id (e.g., parent="link_L1"), and use a relative geometry along the edge.
• Position along the edge uses mxGeometry x as a 1D coordinate from -1 (source endpoint) to +1 (target endpoint):
  • Source-side octet: x="-0.7" — sits ~70% toward the source, near the source router.
  • Target-side octet: x="0.7" — sits ~70% toward the target, near the target router.
• Style: edgeLabel;html=1;align=center;verticalAlign=middle;resizable=0;points=[];fontSize=10;fontColor=#FFFFFF;
• Color matching: When the parent link has a non-white stroke (e.g., orange L2 AC, cyan pseudowire), set fontColor on the octet to match the link color so the octet is read as part of that link's identity.
• Purpose: Allows instant identification of which IP belongs to which router without reading the full subnet label, and survives node repositioning automatically.

4.6 Legend Box

Every diagram must include a legend box with the following properties:

• Position: Bottom-right area of the canvas.

• Fill: Black (#000000).

• Font Color: White (#FFFFFF).

• Border: Rounded, white stroke.

• Style: rounded=1;whiteSpace=wrap;html=1;fillColor=#000000;strokeColor=#FFFFFF;fontColor=#FFFFFF;fontSize=10;align=left;verticalAlign=top;spacingLeft=8;spacingTop=8;

• Content: Key information for reading the diagram:

  • OSPF Area designations (if applicable)
  • Link type indicators (solid = physical, dashed = tunnel)
  • Any cost or metric annotations
  • Protocol identifiers (OSPF Process ID, EIGRP AS, etc.)
  • Role badges present in the diagram (RR, ABR, ASBR, DR, etc.) — see §4.11

• Color the swatch, not the words: The legend renders HTML, so a line that is dotted orange in the diagram must appear as dotted orange in the legend's swatch column. Wrap the dash characters in a <font color="#XXXXXX">…</font> matching the link's strokeColor. Do NOT prefix the description with the word "Orange:" or "Blue:" — the colored swatch is the identifier; the text describes the role.

  Wrong: - - - Orange: EVPN VPWS attachment circuit Right: <font color="#FFA500">- - -</font> EVPN VPWS attachment circuit (L2 AC)

  Use ─── (U+2500) for solid lines, - - - for dashed, . . . for dotted (curved tunnels). One swatch per link/tunnel/zone color in the diagram.

4.7 Reference XML Snippets

Canvas root (always set background):

<mxGraphModel background="#1a1a2e">
  <root>
    <mxCell id="0"/>
    <mxCell id="1" parent="0"/>
    <!-- zone shapes first, then devices, then links -->
  </root>
</mxGraphModel>

Title Cell (rounded white-bordered frame):

<mxCell id="title" value="&lt;font style=&quot;font-size:16px;&quot; color=&quot;#FFFFFF&quot;&gt;&lt;b&gt;Lab N: Title Here&lt;/b&gt;&lt;/font&gt;" style="text;html=1;align=center;verticalAlign=middle;whiteSpace=wrap;strokeColor=default;fillColor=none;rounded=1;" vertex="1" parent="1">
  <mxGeometry x="150" y="20" width="870" height="35" as="geometry" />
</mxCell>

Router icon — label below (hub/top device):

<mxCell id="R1" value="&lt;b style=&quot;color:#FFFFFF;&quot;&gt;R1&lt;/b&gt;&lt;br&gt;&lt;font color=&quot;#CCCCCC&quot; style=&quot;font-size:10px;&quot;&gt;Hub Router&lt;br&gt;Lo0: 10.0.0.1/32&lt;/font&gt;"
  style="sketch=0;points=[[0.5,0,0],[1,0.5,0],[0.5,1,0],[0,0.5,0],[0.145,0.145,0],[0.8555,0.145,0],[0.855,0.8555,0],[0.145,0.855,0]];html=1;aspect=fixed;pointerEvents=1;shape=mxgraph.cisco19.rect;prIcon=router;fillColor=#FAFAFA;strokeColor=#005073;verticalLabelPosition=bottom;verticalAlign=top;align=center;labelPosition=center;"
  vertex="1" parent="1">
  <mxGeometry x="400" y="200" width="60" height="60" as="geometry" />
</mxCell>

Router icon — label to the right:

<mxCell id="R2" value="&lt;b style=&quot;color:#FFFFFF;&quot;&gt;R2&lt;/b&gt;&lt;br&gt;&lt;font color=&quot;#CCCCCC&quot; style=&quot;font-size:10px;&quot;&gt;Branch A&lt;br&gt;Lo0: 10.0.0.2/32&lt;/font&gt;"
  style="sketch=0;points=[[0.5,0,0],[1,0.5,0],[0.5,1,0],[0,0.5,0],[0.145,0.145,0],[0.8555,0.145,0],[0.855,0.8555,0],[0.145,0.855,0]];html=1;aspect=fixed;pointerEvents=1;shape=mxgraph.cisco19.rect;prIcon=router;fillColor=#FAFAFA;strokeColor=#005073;verticalLabelPosition=middle;verticalAlign=middle;align=left;labelPosition=right;"
  vertex="1" parent="1">
  <mxGeometry x="600" y="400" width="60" height="60" as="geometry" />
</mxCell>

White Connection Line:

<mxCell id="link_R1_R2" value="" style="endArrow=none;html=1;strokeWidth=2;strokeColor=#FFFFFF;fillColor=#f5f5f5;" edge="1" parent="1" source="R1" target="R2">
  <mxGeometry relative="1" as="geometry" />
</mxCell>

IP Last Octet Labels (edge-parented — moves with the link/node):

<!-- Source-side octet: parent = link cell id, x = -0.7 along the edge -->
<mxCell id="link_R1_R2_src_oct" value=".1" style="edgeLabel;html=1;align=center;verticalAlign=middle;resizable=0;points=[];fontSize=10;fontColor=#FFFFFF;" vertex="1" connectable="0" parent="link_R1_R2">
  <mxGeometry x="-0.7" relative="1" as="geometry">
    <mxPoint as="offset" />
  </mxGeometry>
</mxCell>
<!-- Target-side octet: x = +0.7 -->
<mxCell id="link_R1_R2_dst_oct" value=".2" style="edgeLabel;html=1;align=center;verticalAlign=middle;resizable=0;points=[];fontSize=10;fontColor=#FFFFFF;" vertex="1" connectable="0" parent="link_R1_R2">
  <mxGeometry x="0.7" relative="1" as="geometry">
    <mxPoint as="offset" />
  </mxGeometry>
</mxCell>

Role Badge (e.g., RR overlay on a router):

<!-- Place AFTER the device cell so it renders on top. Position over the icon's upper-right corner. -->
<mxCell id="P1_rr_badge" value="&lt;b style=&quot;color:#FFD700;font-size:11px;&quot;&gt;RR&lt;/b&gt;" style="text;html=1;align=center;verticalAlign=middle;strokeColor=#FFD700;fillColor=#333300;rounded=1;fontSize=11;fontStyle=1;" vertex="1" parent="1">
  <mxGeometry x="595" y="205" width="32" height="20" as="geometry" />
</mxCell>

Legend Box (colored swatches that match the diagram's lines):

<mxCell id="legend" value="&lt;b&gt;LEGEND&lt;/b&gt;&lt;br&gt;─── Physical link (white, IS-IS + LDP)&lt;br&gt;&lt;font color=&quot;#FFA500&quot;&gt;- - -&lt;/font&gt; EVPN VPWS attachment circuit (L2 AC)&lt;br&gt;&lt;font color=&quot;#00AAFF&quot;&gt;. . .&lt;/font&gt; EVPN VPWS pseudowire (BGP-signalled)&lt;br&gt;[gray zone] MPLS Core domain&lt;br&gt;&lt;font color=&quot;#FFD700&quot;&gt;[RR badge]&lt;/font&gt; Route Reflector (iBGP EVPN)" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#000000;strokeColor=#FFFFFF;fontColor=#FFFFFF;fontSize=10;align=left;verticalAlign=top;spacingLeft=8;spacingTop=8;arcSize=3;" vertex="1" parent="1">
  <mxGeometry x="620" y="650" width="350" height="135" as="geometry" />
</mxCell>

Each swatch's <font color="..."> MUST match the corresponding link's strokeColor, the role badge's strokeColor, or the zone's strokeColor. If you change a line color in the diagram, update the matching swatch in the legend.

4.8 Layout Rules — Avoiding Link Overlap

Critical Rule: A connection line must NEVER visually cross through an intermediate device. This happens when three or more devices share the same X coordinate in a vertical chain and a "bypass" link connects non-adjacent devices.

Problem Pattern (DO NOT USE when bypass links exist):

  R1 (400, 200)    ← bypass link R1→R3 draws a straight
  |                   vertical line through R2
  R2 (400, 400)
  |
  R3 (400, 600)

Solution: When a bypass link exists between two devices that have intermediate devices at the same X coordinate, offset the intermediate device(s) horizontally to create a triangle or staggered layout.

Correct Pattern — Offset R2 to create a clear triangle:

       R1 (400, 200)
      / \
     /   \              R1→R3 link has clear path on the left
    /     \
  R2 (500, 400)        R2 shifted right by ~100px
    \
     \
      R3 (400, 600)

General Rules:

1. Detect bypass links: Before placing devices, check if any link connects two devices that skip over intermediate devices in the vertical chain.
2. Offset intermediate devices: Shift the intermediate device(s) horizontally by at least 100px to create visual separation.
3. Preferred offset direction: Shift RIGHT (increase X) unless the right side is occupied by another device (R4, R7), in which case shift LEFT.
4. Label adjustment: When a device is offset, its label position must follow — labels go to the LEFT of the device icon, or ABOVE if the left side is crowded.
5. Octet label adjustment: IP last-octet labels must be repositioned to remain near their respective interface endpoints after any coordinate changes.

When bypass links are NOT present (pure linear chain R1→R2→R3 with no R1→R3 link), the standard vertical column layout at the same X is fine.

4.9 Overlay / Tunnel Lines

Tunnel overlays represent logical connections that run on top of the physical topology. They must be visually distinct from physical links.

4.9.1 Style Rules

4.9.2 Color Coding by Tunnel Type

4.9.3 Arc Routing — Curving Over Intermediate Devices

Tunnel lines must arc above the physical topology, not route through intermediate devices.

Algorithm: Use two waypoints that position the line above both endpoints:

• arc_y = min(source_y, target_y) - 100 (100px above the higher device)
• Waypoint 1: (source_x + 39, arc_y) — above source icon center
• Waypoint 2: (target_x + 39, arc_y) — above target icon center

Example XML (GRE tunnel R1→R6, R1 at 400,200 and R6 at 200,200):

<mxCell id="tunnel_R1_R6" value="" style="endArrow=none;html=1;strokeWidth=1;strokeColor=#FFFFFF;fillColor=none;dashed=1;dashPattern=1 4;curved=1;exitX=0.5;exitY=0;exitDx=0;exitDy=0;entryX=0.5;entryY=0;entryDx=0;entryDy=0;" edge="1" parent="1" source="R1" target="R6">
  <mxGeometry relative="1" as="geometry">
    <Array as="points">
      <mxPoint x="439" y="100"/>
      <mxPoint x="239" y="100"/>
    </Array>
  </mxGeometry>
</mxCell>
<mxCell id="tunnel_R1_R6_lbl" value="Tunnel8 - Tunnel8&#10;172.16.16.0/30&#10;[GRE]" style="edgeLabel;html=1;align=center;verticalAlign=middle;resizable=0;points=[];fontSize=10;" vertex="1" connectable="0" parent="tunnel_R1_R6">
  <mxGeometry relative="1" as="geometry"><mxPoint as="offset"/></mxGeometry>
</mxCell>

4.9.4 Tunnel Endpoint Octet Labels

Each tunnel arc endpoint must have a small .1 / .2 last-octet label near the source/target endpoints. Use the same edge-parented pattern as §4.5 so the labels follow the tunnel when nodes move.

• Parent: the tunnel cell's id (e.g., parent="tunnel_R1_R6_0").
• Position along the arc: x="-0.7" (source-side) and x="0.7" (target-side).
• Style: edgeLabel;html=1;align=center;verticalAlign=middle;resizable=0;points=[];fontSize=10;fontColor=<TUNNEL_COLOR>; — match the tunnel color (e.g., #00AAFF for VXLAN/pseudowire) so the octets read as part of the overlay.

Example XML (cyan VXLAN/pseudowire tunnel R1→R6):

<mxCell id="tunnel_R1_R6_0_src_octet" value=".1"
  style="edgeLabel;html=1;align=center;verticalAlign=middle;resizable=0;points=[];fontSize=10;fontColor=#00AAFF;"
  vertex="1" connectable="0" parent="tunnel_R1_R6_0">
  <mxGeometry x="-0.7" relative="1" as="geometry"><mxPoint as="offset"/></mxGeometry>
</mxCell>
<mxCell id="tunnel_R1_R6_0_dst_octet" value=".2"
  style="edgeLabel;html=1;align=center;verticalAlign=middle;resizable=0;points=[];fontSize=10;fontColor=#00AAFF;"
  vertex="1" connectable="0" parent="tunnel_R1_R6_0">
  <mxGeometry x="0.7" relative="1" as="geometry"><mxPoint as="offset"/></mxGeometry>
</mxCell>

4.9.5 Legend Requirements

The legend box must list each tunnel type present in the diagram:

Legend
--- Physical Link
....... GRE Tunnel (white)
....... IPsec VPN (red)
....... MPLS (orange)
EIGRP AS 100

4.9.6 Baseline YAML Structure

Tunnel overlays are defined in the tunnel_overlays top-level section of baseline.yaml, keyed by lab number:

tunnel_overlays:
  - lab: 8
    type: gre
    source: R1:Tunnel8
    target: R6:Tunnel8
    subnet: 172.16.16.0/30
    description: GRE Tunnel for EIGRP over VPN

4.10 Protocol Domain Zones (Area / AS Overlays)

Domain zones represent logical groupings of devices and links that share a routing boundary — OSPF areas, BGP autonomous systems, VRFs, MPLS domains, etc. They are drawn as dashed, semi-transparent colored ellipses that sit visually behind all routers and links.

4.10.1 Drawing Order — Zones First

Zone shapes must be placed before (earlier in the XML than) all router cells and link cells. Draw.io renders cells in document order; placing zones first ensures they appear behind devices and lines.

4.10.2 Zone Shape Style

All zone shapes share the same base style pattern:

rounded=1;arcSize=5;whiteSpace=wrap;html=1;dashed=1;strokeWidth=2;opacity=35;
fontSize=12;fontStyle=1;fontColor=#FFFFFF;
strokeColor=<COLOR>;fillColor=<DARK_FILL>;
verticalAlign=<top|bottom>;spacingTop=6;

• rounded=1;arcSize=5 — slightly rounded rectangle (NOT ellipse; arcSize=5 gives barely-softened corners)
• dashed=1 — boundary is always dashed (never solid)
• opacity=35 — semi-transparent so routers and links show through
• fontColor=#FFFFFF — white text so label reads against dark canvas
• fillColor — a dark-tinted version of the stroke color (see table below)
• verticalAlign — place label at top if devices occupy the bottom of the zone, bottom if devices are near the top

4.10.3 Color Table by Domain Type

Rule: Each distinct domain gets a unique color from the table. When multiple OSPF areas are present, Area 0 is always blue; assign subsequent normal areas green; assign stub/NSSA areas orange/purple. For BGP, assign one color per AS — rotate through the BGP rows in order.

4.10.4 Zone Sizing and Positioning

• The ellipse must fully enclose all devices and links that belong to the zone, with at least 20–30px of padding around the outermost device edges.
• Zones that share a device (e.g., an ABR in Area 0 and Area 1) will overlap — this is correct and expected. The semi-transparent fills stack and show the shared boundary visually.
• Zones for larger areas (backbone Area 0) are typically wider and taller; peripheral areas (stub, NSSA) are smaller ellipses containing only their few devices.

4.10.5 Zone Label Placement

• The label text inside the ellipse identifies the zone name and type.
• Use verticalAlign=top to place the label at the top of the ellipse when devices sit in the lower portion.
• Use verticalAlign=bottom to place the label at the bottom when devices sit near the top of the ellipse.
• Never center the label vertically if it would overlap a router icon.

4.10.6 Reference XML Snippet — Zone Shapes

OSPF Area 0 (Backbone) — blue:

<!-- Draw zones FIRST — before any router or link cells -->
<mxCell id="area0_shape" value="Area 0&#10;(Backbone)"
  style="rounded=1;arcSize=5;whiteSpace=wrap;html=1;dashed=1;strokeColor=#1565C0;strokeWidth=2;fillColor=#1a3a5c;opacity=35;fontSize=12;fontStyle=1;verticalAlign=top;fontColor=#FFFFFF;spacingTop=6;"
  vertex="1" parent="1">
  <mxGeometry x="10" y="80" width="555" height="260" as="geometry" />
</mxCell>

OSPF Area 1 (Normal) — green:

<mxCell id="area1_shape" value="Area 1"
  style="rounded=1;arcSize=5;whiteSpace=wrap;html=1;dashed=1;strokeColor=#2E7D32;strokeWidth=2;fillColor=#1b3d27;opacity=35;fontSize=12;fontStyle=1;verticalAlign=bottom;fontColor=#FFFFFF;spacingTop=6;"
  vertex="1" parent="1">
  <mxGeometry x="55" y="290" width="510" height="400" as="geometry" />
</mxCell>

OSPF Stub / Totally Stubby Area — orange:

<mxCell id="area2_shape" value="Area 2&#10;(Totally Stubby)"
  style="rounded=1;arcSize=5;whiteSpace=wrap;html=1;dashed=1;strokeColor=#E65100;strokeWidth=2;fillColor=#4a1e00;opacity=35;fontSize=12;fontStyle=1;verticalAlign=top;fontColor=#FFFFFF;spacingTop=6;"
  vertex="1" parent="1">
  <mxGeometry x="448" y="335" width="310" height="125" as="geometry" />
</mxCell>

BGP Autonomous System — teal (local AS) and orange (peer AS):

<!-- Local AS -->
<mxCell id="as65001_shape" value="AS 65001&#10;(iBGP)"
  style="rounded=1;arcSize=5;whiteSpace=wrap;html=1;dashed=1;strokeColor=#00838F;strokeWidth=2;fillColor=#003d45;opacity=35;fontSize=12;fontStyle=1;verticalAlign=top;fontColor=#FFFFFF;spacingTop=6;"
  vertex="1" parent="1">
  <mxGeometry x="20" y="55" width="420" height="340" as="geometry" />
</mxCell>

<!-- Peer AS -->
<mxCell id="as65002_shape" value="AS 65002"
  style="rounded=1;arcSize=5;whiteSpace=wrap;html=1;dashed=1;strokeColor=#F57F17;strokeWidth=2;fillColor=#4a2700;opacity=35;fontSize=12;fontStyle=1;verticalAlign=top;fontColor=#FFFFFF;spacingTop=6;"
  vertex="1" parent="1">
  <mxGeometry x="500" y="55" width="280" height="240" as="geometry" />
</mxCell>

4.10.7 Legend Requirements for Zones

When zone shapes are present, the legend box must list each zone with its color. Format:

Legend
--- Physical Link
[blue dashed] Area 0 (Backbone)
[green dashed] Area 1 (Normal)
[orange dashed] Area 2 (Totally Stubby)
OSPF Process ID: 1

Since Draw.io legend cells are plain text, describe colors in words or use Unicode colored indicators where possible. At minimum, name each zone and its type.

4.10.8 When to Apply Zone Shapes

4.11 Device Role Badges

Role badges are small text overlays attached to a device icon to call out a lab-specific role that the device plays — Route Reflector (RR), Area Border Router (ABR), Designated Router (DR), Autonomous System Boundary Router (ASBR), Provider Edge running XR (XR), etc. They are used in labs where the lab's learning objective hinges on the role.

4.11.1 When to Use a Role Badge

Add a badge when all of the following are true:

• The device's role is the subject of the lab (e.g., "configure P1 as the EVPN route reflector"), not just incidental topology context.
• The role is not obvious from the device's hostname or position. (PE1 already implies "provider edge"; you would not badge it PE.)
• A reader looking at the diagram alone should recognize the role at a glance, without reading the workbook.

Do NOT add badges for:

• Generic topology positions already encoded in the hostname (R1, PE2, CE1, etc.)
• Every device — overuse drowns out the signal. Most labs need 0–2 badges.

4.11.2 Style

4.11.3 Color Table by Role

Pick the row that matches the role. Each role has a stroke (border + text), a dark-tinted fill, and a default label.

Each badge color used in the diagram must appear in the legend with a matching colored swatch (see §4.6).

4.11.4 Reference XML Snippet

<!-- Device cell first... -->
<mxCell id="P1" value="..." style="...mxgraph.cisco19.rect;prIcon=router;..." vertex="1" parent="1">
  <mxGeometry x="545" y="210" width="60" height="60" as="geometry"/>
</mxCell>
<!-- ...then the badge, so it renders on top of the icon -->
<mxCell id="P1_rr_badge" value="&lt;b style=&quot;color:#FFD700;font-size:11px;&quot;&gt;RR&lt;/b&gt;"
  style="text;html=1;align=center;verticalAlign=middle;strokeColor=#FFD700;fillColor=#333300;rounded=1;fontSize=11;fontStyle=1;"
  vertex="1" parent="1">
  <mxGeometry x="595" y="205" width="32" height="20" as="geometry"/>
</mxCell>

4.11.5 Legend Entry

Every badge color present in the diagram needs a legend entry using the swatch convention from §4.6:

<font color="#FFD700">[RR badge]</font> Route Reflector (iBGP EVPN)
<font color="#1E88E5">[ABR badge]</font> OSPF Area Border Router

--# 5. Workflow

Creating a New Diagram

1. Open Draw.io (Desktop or Web).
2. Create the diagram following the Visual Style Guide (Section 4).
3. Validation Checklist:
   • Canvas background is #1a1a2e (set in <mxGraphModel background="#1a1a2e">).
   • Title is at the top center, bold, 16pt, white text, wrapped in a rounded white-bordered frame (strokeColor=default;fillColor=none;rounded=1;) — NOT strokeColor=none.
   • All device icons use mxgraph.cisco19.rect;prIcon=<type> — NOT the old mxgraph.cisco.routers.router shapes.
   • Device labels are embedded in the device cell value as HTML (white bold hostname + gray role/IP). No separate label cells.
   • Label position uses labelPosition= / verticalLabelPosition= attributes, following the Empty Side Rule (Section 4.3.1).
   • All connection lines are white (#FFFFFF), strokeWidth=2.
   • Every device has a hostname, role, and Loopback IP.
   • Every link has interface names on BOTH ends.
   • Every interface has a last octet label (.1, .2), and each octet is parented to its link cell (parent="link_<id>" with mxGeometry x="±0.7" relative="1") — NOT to canvas root with absolute X/Y. Octets must move with the link. (See §4.5.)
   • Subnet ID is visible on every link (centered edge label).
   • No link visually crosses through an intermediate device (see Section 4.8).
   • Tunnel overlays use thin colored dotted lines and arc above physical devices (see Section 4.9).
   • Tunnel endpoint octets (.1 / .2) are also edge-parented to the tunnel cell (§4.9.4).
   • Protocol domain zones (OSPF areas, BGP AS, VRFs) drawn as rounded=1;arcSize=5 dashed semi-transparent boxes — placed FIRST in XML so they render behind routers and links (see Section 4.10). Do NOT use ellipse.
   • Each zone uses the correct color from the §4.10.3 table (blue=backbone, green=normal, orange=stub, teal=BGP local AS, etc.).
   • Zone boxes fully enclose their member devices with ≥20px padding; overlapping zones are correct at ABR/ASBR boundaries.
   • Role badges added for any device whose role is the subject of the lab (RR, ABR, DR, etc.); badge cell placed AFTER the device cell so it renders on top (§4.11). Skip badges for roles already implied by the hostname.
   • Legend box is present (black fill, white text, bottom-right) and lists zone types and tunnel colors where applicable.
   • Legend swatches use HTML colors that match the diagram (<font color="#FFA500">- - -</font>) — do NOT name the color in words ("Orange:") since the swatch itself is the identifier (§4.6).
4. Save the editable file as .drawio in the appropriate subdirectory.

Updating a Diagram

1. Open the existing .drawio file.
2. Make necessary modifications.
3. Validate against the checklist above.
4. Save the .drawio file.

-# Common Issues

--# Zone ellipses cover (obscure) routers and links

• Cause: Zone shape cells were placed after router and link cells in the XML, causing them to render on top of everything.
• Solution: Move all zone mxCell elements to appear before the first router cell in the XML. Draw.io renders in document order — zones must come first.

--# Zone ellipse does not enclose all member devices

• Cause: Ellipse geometry was sized for the routers but did not account for labels or link endpoints extending beyond the icon bounds.
• Solution: Extend the ellipse by at least 20–30px beyond the outermost device icon on every side. Check that interface octet labels near the zone boundary are also inside the ellipse.

--# Device icons look wrong (plain circle/router silhouette instead of Cisco19 style)

• Cause: Old mxgraph.cisco.routers.router shape used instead of mxgraph.cisco19.rect;prIcon=router.
• Solution: Replace the device style with the cisco19 string from §4.2. The cisco19 shapes render as a white/light rectangle with a teal border and an embedded icon — they do NOT look like the old blue-filled silhouettes.

--# Zone shapes are ovals instead of boxes

• Cause: ellipse style used instead of rounded=1;arcSize=5.
• Solution: Replace ellipse; with rounded=1;arcSize=5; in the zone cell style. arcSize=5 gives barely-softened rectangular corners — the shapes should look like boxes, not ovals.

--# Connection lines are black instead of white

• Cause: Default Draw.io line color was used without applying the style guide.
• Solution: Select all connection lines and apply strokeColor=#FFFFFF;strokeWidth=2 from Section 4.4. Run scripts/generate_topo.py to auto-generate a compliant diagram from baseline.yaml.

--# Link visually crosses through an intermediate device

• Cause: Three or more devices share the same X coordinate and a bypass link connects non-adjacent ones.
• Solution: Offset the intermediate device(s) horizontally by at least 100px to create a triangle or staggered layout. See Section 4.8 for the full rule and example.

--# Device label overlaps a connection line

• Cause: Label was placed on the same side as one or more connected links.
• Solution: Apply the Empty Side Rule (Section 4.3.1) — place the label on the side with no connections exiting the icon.

--# Octet labels (.1, .2) get left behind when a node is moved

• Cause: Octets were placed as absolute-positioned cells with parent="1" and an (x, y) canvas coordinate. The link reroutes when its endpoint moves, but the octet stays where it was.
• Solution: Re-parent each octet to the link cell (parent="link_<id>") and replace the geometry with <mxGeometry x="-0.7" relative="1"> for the source-side octet and x="0.7" for the target-side. See §4.5.

--# Legend says "Orange:" but the swatch is white

• Cause: The legend's dash glyphs were left as default (white) text and the line color was named in words instead.
• Solution: Wrap the dashes in <font color="#XXXXXX">…</font> matching the link's strokeColor, and drop the color word from the description. See §4.6.

--# Role badge renders behind the router icon

• Cause: Badge cell was placed before the device cell in the XML. Draw.io renders in document order.
• Solution: Move the badge cell to immediately after the device cell so it draws on top. See §4.11.4.

--# generate_topo.py produces incorrect output

• Cause: baseline.yaml is missing required fields (links, device coordinates, or interface definitions).
• Solution: Verify baseline.yaml has complete core_topology.links with source, target, and subnet for every link. Check for missing loopback0 values on devices.