# How to show circle on two edges to show PC, VPC connection

**URL:** <https://forum.graphviz.org/t/how-to-show-circle-on-two-edges-to-show-pc-vpc-connection/1272>\
**Category:** Help\
**Created:** [August 4, 2022, 4:47am UTC](https://forum.graphviz.org/t/how-to-show-circle-on-two-edges-to-show-pc-vpc-connection/1272 "2022-08-04T04:47:13Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Konika](https://avatars.discourse-cdn.com/v4/letter/k/ed8c4c/32.png) [@Konika](https://forum.graphviz.org/u/Konika)\
**Post date:** [August 4, 2022, 4:47am UTC](https://forum.graphviz.org/t/how-to-show-circle-on-two-edges-to-show-pc-vpc-connection/1272/1 "2022-08-04T04:47:13Z")

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I am trying to generate the network topology diagrams and wanted to show circle on two edges to show the PC, VPC connections. Please help me  
 ![Screenshot 2022-08-04 at 10.16.41 AM](https://global.discourse-cdn.com/graphviz/original/1X/ea742651d5ff2383cdcb26ef5a36f228e9d5f18f.png)

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**Author:** ![steveroush](https://avatars.discourse-cdn.com/v4/letter/s/a9adbd/32.png) [@steveroush](https://forum.graphviz.org/u/steveroush)\
**Post date:** [August 4, 2022, 3:18pm UTC](https://forum.graphviz.org/t/how-to-show-circle-on-two-edges-to-show-pc-vpc-connection/1272/2 "2022-08-04T15:18:00Z")

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The big trick is to use a colorlist ([colorList | Graphviz](https://graphviz.org/docs/attr-types/colorList/)) to guarantee parallel lines. Two “white” lines are in the list to produce greater separation between the two black lines.

```auto
graph P{
  splines=false
  ranksep= .25
  node [shape=rect]
  A B
  // sizing set by eyeball
  C1 [shape=ellipse width=.35 height=.2 fixedsize=true label=""]
  // each edge is drawn as two black lines, separated by two "white" lines
  edge [color="black:white:white:black"]
  A -- C1 -- B
}

```

Giving:  
 ![parallelEdges0](https://global.discourse-cdn.com/graphviz/original/1X/ddf9736f32e4aadb8e2e3f2b82ae9e539d5b39de.png)