From: Mark Stover (mstover@xxxxxxxxx)
Date: Mon Jan 15 2001 - 22:06:53 GMT-3
Perfect example of why you shouldn't aggregate someone else's address...
I have two ideas, haven't had a chance to try either:
1.
access-list 10 deny 170.0.0.0
access-list 10 permit any
router bgp 5
distribute list 10 in
2.
You could policy route the 170.x.x.x subnets that aren't local.
Mark
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> Connary, Julie Ann
> Sent: Monday, January 15, 2001 10:50 AM
> To: ccielab@groupstudy.com
> Subject: BGP aggregates and IGRP default networks
>
>
> Hi All,
>
>
> I have one I cannot figure out. I have an IGRP router that is using a
> default-network to
> overcome subnet mask length differences into my OSPF network.
> Works great
> until I
> did the BGP part of the lab which requires an aggregate address. The
> aggregate address puts
> a static route to null 0 in my routing table and I can no
> longer default
> route to the OSPF network:
>
>
>
> OSPF Network with 24, 28 and 29 bit masks of 170.100.x.x
> |
> |
> |
> Router 5 - OSPF and IGRP
> |
> | 170.100.1.x/24
> |
> Frame-relay point-to-point link
> |
> |
> |
> Router 4 - running IGRP and BGP
> ip default-network 200.0.5.0
> router bgp 5
> no auto-summary
> network 170.100.1.0 mask 255.255.255.0
> aggregate-address 170.0.0.0 255.0.0.0 summary-only
>
>
> Now I get the following routing table on R4 and cannot get to
> any of the
> non 24 bit subnets in OSPF.
> How do I fix WITHOUT using static routes on R5 that
> "summarize" the 28 and
> 29 bit subnets to
> 24 bits and redistribute them into IGRP. Can I stop the
> aggregate address
> from being entered into
> R4's routing table. I really only want to advertise that
> aggregate to my
> EBGP neighbor anyways.
>
> Gateway of last resort is 170.100.1.5 to network 210.0.5.0
>
> 170.100.0.0/24 is subnetted, 9 subnets
> C 170.100.200.0 is directly connected, Ethernet0
> I 170.100.233.0 [100/10476] via 170.100.1.5, 00:01:03, Serial0
> I 170.100.129.0 [100/10476] via 170.100.1.5, 00:01:03, Serial0
> I 170.100.150.0 [100/10476] via 170.100.1.5, 00:01:03, Serial0
> I 170.100.68.0 [100/10476] via 170.100.1.5, 00:01:03, Serial0
> I 170.100.67.0 [100/10476] via 170.100.1.5, 00:01:03, Serial0
> I 170.100.64.0 [100/10476] via 170.100.1.5, 00:01:04, Serial0
> I 170.100.65.0 [100/10476] via 170.100.1.5, 00:01:04, Serial0
> C 170.100.1.0 is directly connected, Serial0
> 1.0.0.0/24 is subnetted, 1 subnets
> C 1.1.1.0 is directly connected, Loopback0
> I* 210.0.5.0/24 [100/10476] via 170.100.1.5, 00:01:04, Serial0
> B 205.15.150.0/24 [20/0] via 170.100.200.7, 1d18h
> B 170.0.0.0/8 [200/0] via 0.0.0.0, 1d18h, Null0
> <---------------this
> entry is stopping my default-network from being usefull.
> tserve#ping 170.100.42.241
>
> Type escape sequence to abort.
> Sending 5, 100-byte ICMP Echos to 170.100.42.241, timeout is
> 2 seconds:
> .....
> Success rate is 0 percent (0/5)
> tserve#
>
>
> Thanks,
>
> Julie Ann
>
> --------------------------------------------------------------
> ----------
> Julie Ann Connary
> | | Network Consulting Engineer
> ||| ||| Federal Support Program
> .|||||. .|||||. 13635 Dulles
> Technology Drive,
> Herndon VA 20171
> .:|||||||||:.:|||||||||:. Pager: 1-888-642-0551
> c i s c o S y s t e m s Email: jconnary@cisco.com
>
> --------------------------------------------------------------
> ----------
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