From: Istvan Szabo \(isszabo\) (isszabo@cisco.com)
Date: Sun May 20 2007 - 17:29:02 ART
Hi group,
Help me out with this please, I've been troubleshooting for several
hours but cannot come up with a solution! (this scenario is part of IE
core lab 5 btw. Now I'm describing a partial setup, original was full of
virtual links, I elinimated the irrelevent part. Was quite tricky
because the whole problem arose only after redistribution)
I have 3 routers in a FR hub and spoke topology:
R2(spoke) ----- R5 (hub) --------- R1 (spoke)
I was constrained to do PPP over FR with multipoint interfaces. I
configured PPPoFR between R2-R5 and R1-R5. Also, requrement was to use
the same subnet ---> same virtual template on hub for both PPP sessions.
It works fine, they exchange routes all is working till I introduce R1
as an ASBR. When I do so, I noticed that the E1-2 routes are going wrong
at R5:
Rack1R5#sh ip route
O E1 128.1.14.0/24 [110/21] via 128.1.125.1, 00:00:02,
Virtual-Access2
[110/21] via 128.1.125.1, 00:00:02,
Virtual-Access1
This means, that instead of going to the directly connected R1, there is
an invalid path present for the other virtual-access interface as well.
No wonder why since:
Rack1R5#sh ip ospf border
i 150.1.1.1 [1] via 128.1.125.1, Virtual-Access1, ABR/ASBR, Area 0, SPF
289
i 150.1.1.1 [1] via 128.1.125.1, Virtual-Access2, ABR/ASBR, Area 125,
SPF 91
I've tried to replace the ppp sessions with simple FR and then its good:
(FR maps it to correct DLCI)
i 150.1.1.1 [64] via 128.1.125.1, Serial0/0/0, ABR/ASBR, Area 0, SPF 283
i 150.1.1.1 [64] via 128.1.125.1, Serial0/0/0, ABR/ASBR, Area 125, SPF
85
How can I solve this? Is there any means to make it work with these
restrictions?
Thanks a lot! Istvan
In case it is needed, my configs are:
R5:
interface Serial0/0/0.1 multipoint
frame-relay interface-dlci 501 ppp Virtual-Template1
interface Virtual-Template1
ip address 128.1.125.5 255.255.255.0
ip ospf network point-to-multipoint
router ospf 1
log-adjacency-changes
area 125 virtual-link 150.1.1.1
redistribute rip subnets
passive-interface FastEthernet0/1
network 128.1.125.0 0.0.0.255 area 125
network 150.1.0.0 0.0.255.255 area 765
R1:
interface Serial0/0/0.1 multipoint
frame-relay interface-dlci 105 ppp Virtual-Template1
no frame-relay inverse-arp
interface Virtual-Template1
ip address 128.1.125.1 255.255.255.0
ip ospf network point-to-multipoint
router ospf 1
log-adjacency-changes
area 125 filter-list prefix DENY in
area 125 virtual-link 150.1.5.5
redistribute eigrp 10 metric-type 1 subnets
network 128.1.125.0 0.0.0.255 area 125
network 128.1.136.0 0.0.0.255 area 0
network 150.1.0.0 0.0.255.255 area 321
R2:
interface Serial0/0/0.1 multipoint
frame-relay interface-dlci 205 ppp Virtual-Template1
no frame-relay inverse-arp
interface Virtual-Template1
ip address 128.1.125.2 255.255.255.0
ip ospf network point-to-point
ip ospf cost 40000
ip ospf hello-interval 30
router ospf 1
log-adjacency-changes
area 12 stub
network 128.1.27.0 0.0.0.255 area 12
network 128.1.57.0 0.0.0.255 area 0
network 128.1.125.0 0.0.0.255 area 125
network 150.1.0.0 0.0.255.255 area 321
This archive was generated by hypermail 2.1.4 : Fri Jun 01 2007 - 06:55:21 ART