Is it possible to get multiple is-is adjacencies on a same port with VOSS7 on VSP 7200 series switches ?

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This question because we use an operator's L2 VPN tunnels to interconnect our VSP on different remote sites. Instead of using a different tunnel for each adjacencie, it would be easier that switches could see each other via same L2 tunnel, forming so a full mesh design.

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Posted 4 weeks ago

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Ludovico Stevens, Employee

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SPB ISIS adjacencies are point-point only. If doing Fabric Connect SPB over a WAN, you will need to use Fabric Extend. There are 2 Fabric Extend modes, using VXLAN and using VLAN translation (of the BVIDs). In your case it sounds like the operator is giving you a VPLS (L2 any-any) service. You will thus need to use the Fabric Extend VXLAN mode (to male it look like point-point to SPB). In this mode, you set the FE source IP on the VSP, and then created FE ISIS adjacency towards remote IP addresses using logical ISIS interfaces. A VXLAN tunnel is used for each of those remote adjacencies. And yes, you can now have all your logical ISIS adjacencies running on the same physical Ethernet port.
Hi Ludovico,

Thanks for your fast and precise response. We'll work on a such design in the next weeks.

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Mark Colley

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Ludovico - can you expand a little on the "other" mode - VLAN translation? I have a similar issue where my provider gives me L2 bridging to remote location, but I can't use my existing BVLAN IDs. Is this possible, or is IP tunnel the only solution?
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Tomasz

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Mark,

if your provider gives you a set of VLANs, you can translate your BVIDs to those with use of IS-IS logical interface. Each link (hub & spoke or mesh point-to-point) shall be a pair of logical interfaces that map SPBM BVIDs to carrier VIDs.

The entire magic is here:
router isis
logical-intf isis 1 vid 101,102 primary-vid 101 port 1/1 name l2tun_1to3
Where 1 is just logical interface ID and vid is a list of carrier VIDs to have your BVIDs translated to. You can have mlt instead of a port if applicable.

You can then test with:
show isis logical-interface
show isis interface
show isis adjacencies
Please remember of the MTU, 1544B minimum at your provider.
Please remember to have unique VIDs for each port/MLT.

Further details can be found on pages 42-43 of this doc: https://documentation.extremenetworks.com/VOSS/SW/71x/9035537_ConfigFabBasicsVOSS_7.1_CG.pdf

Hope that helps,
Tomasz
(Edited)
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Mark Colley

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Thank you for the quick response. We have this set up in a lab but I don't think the MTU was investigated. I'll check that and let you know.
Thanks again.

--Mark
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Ludovico Stevens, Employee

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> my provider gives me L2 bridging to remote location

If you want to use the Fabric Extend vlan translation mode, the provider must not only give you L2 bridging to the remote location, but it has to be a point-point service which means you have only 2 (not more) VSPs forming an adjacency over that L2 bridging service and, because of the way SPB operates with 2 BVLANs, you'll need the provider to double up that L2 point-point service for 2 separate VLAN-IDs.
The other thing to keep in mind, as you typically will have more than 1 remote location being FE connected back into a central location, all these point-point circuits will be terminated into a single Ethernet port on the VSP of the central location. At the central location, the WAN provider will naturally consolidate all those point-point circuits into a single Ethernet port using Q-in-Q (i.e. by pushing a 2nd Q-tag onto packets which are already Q-tagged), but this will NOT work. We do not support Q-in-Q encapsulation on the VSP in the FE VLAN translation mode. You need to make sure the provider presents the circuits using regular 802.1ad Q-tagging, i.e. the VSP gets packets with single Q-tag, the one that you configure in the ISIS logical interface.
The above mode is less popular, as it is rather fiddly, and customers tend to prefer more simple L2 ELAN or IPVPN type services from their providers.

Now, if instead, you meant that the provider is giving you a L2 bridging service to ALL locations (i.e. not a bunch of point-points, but an ELAN type service) then the right Fabric Extend mode to use is the regular one using VXLAN encapsulation. The WAN provider will give you a VLAN-id for each location (they might be the same or they might be different) but these will all be bridged together in one single broadcast domain. In this mode you simply alocate a Fabric Extend Source IP on each VSP (these IPs will naturally be on the same IP subnet since the provider service is L2; for each VSP this IP will be presented to the provider using the VLAN-id specified by the provider at that location) then you create your logical ISIS interfaces pointing to the various VSP FE IPs; this ends up producing VXLAN IP point-point tunnels within which SPB operates.