I believe ISIS DIS election is based upon priority and then SNPA (MAC or
DLCI), and not loopback IPs.

Anyway, I wonder if the problem might be that your hub router is using the
main interface as opposed to a point-to-multipoint sub-interface.

Eric


On Thu, Mar 31, 2011 at 9:50 AM, Vitkovsky, Adam <[email protected]>wrote:

>  Hi there,
>
>
>
> I have hub and spoke topology over main serial interfaces on hub and spokes
> and ISIS L1 running through
>
> Name loopback    int-ip
>
> R1    1.1.1.1           10.0.0.1
>
> R2    2.2.2.2           10.0.0.2
>
> R3    3.3.3.3           10.0.0.3
>
> R4    4.4.4.4           10.0.0.4
>
>
>
> ISIS should behave as on broadcast medium in this setup –hub has the
> highest loopback ip 4.4.4.4 so it became a DIS and is indeed sending the
> CSNP periodically
>
> After initial convergence all the routers have the same topology tables
> with all the router’s loopback IPs
>
>
>
> Problem is only the hub loopback ip makes it into the routing table on
> spokes
>
>
>
> Hub has all 3 spoke’s loopbacks in its routing table -no issues there and
> I’m able to ping hub’s loopback from each spoke
>
>
>
> -the only thing I could think of was that maybe on broadcast medium isis
> won’t install prefixes from routers with which it doesn’t have an adjacency
>
> (cause isis forms an adjacency with all the routers on b-cast medium –but
> for nbma it’s not –so only prefixes from hub where installed in RIB)
>
>
>
> Please let me know your thoughts
>
> Thank you very much
>
>
>
> ----------------
>
> Spoke conf:
>
> interface Serial1/0
>
>  ip address 10.0.0.1 255.255.255.0
>
>  ip router isis 1
>
>  encapsulation frame-relay
>
>  serial restart-delay 0
>
>  frame-relay map ip 10.0.0.4 104
>
>  frame-relay map clns 104 broadcast
>
>  no frame-relay inverse-arp
>
> !
>
> router isis 1
>
>  net 49.0001.0000.0000.0001.00
>
>  is-type level-1
>
>  log-adjacency-changes all
>
>  passive-interface Loopback0
>
>
>
> ----------------
>
> hub config:
>
> interface Serial1/0
>
>  ip address 10.0.0.4 255.255.255.0
>
>  ip router isis 1
>
>  encapsulation frame-relay
>
>  serial restart-delay 0
>
>  frame-relay map clns 403 broadcast
>
>  frame-relay map clns 402 broadcast
>
>  frame-relay map clns 401 broadcast
>
>  frame-relay map ip 10.0.0.3 403 broadcast  <-the broadcast keyword doesn’t
> need to be there
>
>  frame-relay map ip 10.0.0.2 402 broadcast
>
>  frame-relay map ip 10.0.0.1 401 broadcast
>
>  no frame-relay inverse-arp
>
> !
>
> router isis 1
>
>  net 49.0001.0000.0000.0004.00
>
>  is-type level-1
>
>  log-adjacency-changes all
>
>  passive-interface Loopback0
>
>
>
>
>
>
>
>
>
>
>
> _______________________________________________
> For more information regarding industry leading CCIE Lab training, please
> visit www.ipexpert.com
>
>
_______________________________________________
For more information regarding industry leading CCIE Lab training, please visit 
www.ipexpert.com

Reply via email to