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BGP aggregates and IGRP default networks posted 01/15/2001
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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
            router bgp 5
               no auto-summary
              network mask
                aggregate-address 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 to network is subnetted, 9 subnets
C is directly connected, Ethernet0
I [100/10476] via, 00:01:03, Serial0
I [100/10476] via, 00:01:03, Serial0
I [100/10476] via, 00:01:03, Serial0
I [100/10476] via, 00:01:03, Serial0
I [100/10476] via, 00:01:03, Serial0
I [100/10476] via, 00:01:04, Serial0
I [100/10476] via, 00:01:04, Serial0
C is directly connected, Serial0 is subnetted, 1 subnets
C is directly connected, Loopback0
I* [100/10476] via, 00:01:04, Serial0
B [20/0] via, 1d18h
B [200/0] via, 1d18h, Null0  <---------------this 
entry is stopping my default-network from being usefull.

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to, timeout is 2 seconds:
Success rate is 0 percent (0/5)


Julie Ann

                                         Julie Ann Connary
           |           |                  Network Consulting Engineer
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