[c-nsp] Brocade ICX 7750: VXLAN doesn’t forward broadcasts?

Alex K. nsp.lists at gmail.com
Sat Jul 4 09:08:35 EDT 2015


Hello,

I know this is a Cisco list, but maybe somebody will kindly help me with
Brocade here. I have the following setup:

L2 switch --- ICX 7750 --- SOME IP NETWORK --- ICX 7750 --- L2 switch

The VXLAN setup is really simple:

vlan 100 name TEMP by port
   tagged ethe 1/1/33

interface ethernet 1/1/33
   port-name TEMP
   vxlan vlan 100 vni 100 l2-tunnel 1

interface l2-tunnel 1
   l2-tunnel mode vxlan eline
   l2-tunnel source 1.1.1.1
   l2-tunnel destination 2.2.2.2

Connected to both L2 switches (on each side) there are PCs. Obviously on
the same subnet (since VXLAN is L2 VPN). No PC on either switch is able to
ping a PC on the opposite side – all of them isn’t able to resolve ARP!

But the moment I put a static ARP entry in both PCs, they manage ping and
communicate with each other. Therefore, VXLAN seems to be up, besides not
forwarding ARP requests.

The only difference I see, is ARP requests being sent to broadcast MAC
address. Moreover, each PC is able to ping successfully the appropriate IP
addresses on the switch close to it. So it doesn’t seem to be some L2
configuration/problem with the LAN on each side. Moreover, interestingly
enough,  all MAC addresses  present in all switches across the LAN (yes,
that includes MAC addresses from across the VXLAN). The setup is as simple
as outlined above, and the ping responses stop if I disconnect the 7750
from the IP network between them (proof of the fact the LANs on each side
are indeed communicating with each other across the VXLAN).

Any ideas will be welcomed. Is there anything I need to add to the
configuration for forwarding broadcast requests?

Thank you.


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