Tag Archives: L2 Circuit

Layer 2 Circuit on SRX

I will briefly show how you can set up Layer 2 circuit between two packet-mode SRX boxes on 12.1X46-D10 release. Simply, if you set up a Layer 2 circuit between two sites, you can connect the same subnet between two different geographic location over an MPLS cloud. Look at the following sample topology and assume SRX j29 is in Ankara, which is my hometown 🙂 and j34 (which is in Amsterdam where live currently). I know they are so far 🙁 but we will set up the circuit and j40 will be able to ping 10.0.5.2 address of j35 from its address 10.0.5.1 which are in the same subnets.

l2circuit_vlanccc

First of all my assumptions on this setup;

  • J29,j30 and j34 are forming an MPLS cloud
  • We use LDP for label distribution
  • On this setup all these boxes are in packet mode
  • We don’t care what is on J30 as long as it provides MPLS connectivity, nothing special configured on that device
  • J40 and j35 have no special config, you can put PCs to test the connectivity as well.

Let’s first bring the L2 link UP;

Configure interfaces on PE routers
L2 circuit is established between j29 and j34. Interface configuration is really important as a single mistake doesn’t bring the link up.

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