Re: BGP help needed

From: Alex Dean (Alex.Dean@xxxxxxxxxxxxx)
Date: Wed Aug 04 1999 - 00:36:25 GMT-3


   
For Q1 you need a route to the remote interface on its neighbor. Either use a
static route or another IGP. Once you can ping the interface - then you can us
e it aswith the ebgp multihop command and sepcify an update source.

For Q2, you need to make sure R4 is advertising its loopbacks. Either use a ne
twork statement for them, or use a static route to null 0 (you can effectively
 summarise it with this command) and redistribute it. In practice a more speci
fic route will be used so the route to null will be ignored.

Hope this helps.

Cheers
Alex Dean

>>> "hon-siong chan" <honsiong@hotmail.com> 04/08/99 14:43:50 >>>
I need help on my BGP problems encountered in my own practise lab......Below
is the diagram: (Sorry for the length of question!)

    R1-------R3--------R2
             |
             |
             |
             R4

R1 has 2 loopbacks and 1 serial to R3: int lo0 172.16.4.1/28
                                       int lo1 172.16.6.1/28
                                       int S0 172.16.1.1/24

R2 has 1 loopback & 1 serial to R3: int lo0 172.16.5.1/24
                                    int S0 172.16.2.1/24

R3 has 2 serials to R1/R2 & 1 ethernet to R4: int S0 172.16.1.2/24
                                              int S1 172.16.2.2/24
                                              int e0 172.16.3.1/24

R4 has 1 loopback & 1 ethernet to R3: int lo0 172.16.0.33/27
                                      int e0 172.16.3.2/24

I configured R1,R2 & R3 in BGP AS200, and running OSPF as area 0; while R4
in BGP AS400 only. R3 & R4 are pointing to indirectly connected interfaces;
R3 points to R4's lo0, and R4 points to R3 S0, so I used ebgp-multihop
command & update-source command respectively.I also redistribute BGP AS200
into OSPF area 0.

Q1: When I issued "sh ip bgp neighbor". The state is only Active and no
active TCP connection established.

Only when I point to directly connected interfaces without using
ebgp-multihop & update-souce commands then the link between R3 & R4 is
established???Why?

Q2: I need R2, R3 & R4 to be able to see routes from R1's loopbacks. Do I
need to summarise the 2 loopbacks in R1? What do I need to do?

Any comments are much appreciated....

Regards
HonSiong



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