Hi,
On Wed, 29 Jul 2009 14:38:43 +0700, Ivo Chutkin <open...@bgone.net> wrote:
Hallo Misc,
I need some general clarification about OSPF and BGP behavior.
I have tow border routers, border1(OpenBSD4.4 - stable)and
border2(OpenBSD4.4 -stable), and one core router, core1(OpenBSD4.5 -
stable).
Each border router talk eBGP(full feeds) with one upstream provider and
have iBGP session between them. No problems here.
If your cores advertise default route, they both valid to core. So, ECMP
occured. The Core will randomly select default routes.
There you go. See also netstat -nr and route -nv get default output.
The two borders and the core have ospf session to each other in one area.
Border routers redistribute default to core1.
Core1 redistribute connected to borders.
No problems here as well.
I noticed something strange though.
I start mtr to ibm.com for exampe, on the core1, I get different result
every time I issue the command. See the attached results.
First trace:
Host Loss% Snt Last Avg Best
Wrst StDev
1. border2 0.0% 2 0.3 0.3 0.3 0.3 0.0
2. border1 0.0% 2 0.8 0.8 0.8 0.8 0.0
3. 212.73.129.85 0.0% 1 4.1 4.1 4.1
4.1 0.0
4. 212.162.46.17 0.0% 1 2.6 2.6 2.6
2.6 0.0
5. ae-10-10.ebr1.Frankfurt1.Level3. 0.0% 1 31.6 31.6 31.6
31.6 0.0
6. ae-61-61.csw1.Frankfurt1.Level3. 0.0% 1 31.6 31.6 31.6
31.6 0.0
7. ae-62-62.ebr2.Frankfurt1.Level3. 0.0% 1 31.3 31.3 31.3
31.3 0.0
8. ae-44-44.ebr2.Washington1.Level3 0.0% 1 120.6 120.6 120.6
120.6 0.0
9. ae-62-62.csw1.Washington1.Level3 0.0% 1 124.2 124.2 124.2
124.2 0.0
10. ge-0-3-0-69.bbr1.Washington1.Lev 0.0% 1 121.1 121.1 121.1
121.1 0.0
11. so-1-0-0.mpls2.Raleigh1.Level3.n 0.0% 1 127.5 127.5 127.5
127.5 0.0
12. so-10-0.hsa2.Raleigh1.Level3.net 0.0% 1 126.5 126.5 126.5
126.5 0.0
13. IBM-GS-NA.hsa2.Raleigh1.Level3.n 0.0% 1 127.2 127.2 127.2
127.2 0.0
14. ???
Second trace:
Host Loss% Snt Last Avg Best Wrst
StDev
1. border2 0.0% 1 0.9 0.9 0.9 0.9 0.0
2. 212.36.5.217 0.0% 1 0.8 0.8 0.8
0.8 0.0
3. spectrum-ic-131757-ffm-b10.c.tel 0.0% 1 29.8 29.8 29.8
29.8 0.0
4. ffm-b10-link.telia.net 0.0% 1 29.7 29.7 29.7
29.7 0.0
5. ffm-bb2-link.telia.net 0.0% 1 29.6 29.6 29.6
29.6 0.0
6. prs-bb2-link.telia.net 0.0% 1 42.0 42.0 42.0
42.0 0.0
7. ash-bb2-link.telia.net 0.0% 1 121.4 121.4 121.4
121.4 0.0
8. 192.205.34.209 0.0% 1 127.8 127.8 127.8
127.8 0.0
9. cr1.wswdc.ip.att.net 0.0% 1 164.2 164.2 164.2
164.2 0.0
10. cr2.phlpa.ip.att.net 0.0% 1 158.7 158.7 158.7
158.7 0.0
11. cr2.cl2oh.ip.att.net 0.0% 1 157.5 157.5 157.5
157.5 0.0
12. cr1.sl9mo.ip.att.net 0.0% 1 163.0 163.0 163.0
163.0 0.0
13. 12.122.142.29 0.0% 1 158.4 158.4 158.4
158.4 0.0
14. 12.125.74.74 0.0% 1 160.3 160.3 160.3
160.3 0.0
15. ???
The route is changed every time I issue the mtr command.
It also happens with yahoo and probably many other.
Is this behavior normal or there is something wrong with my
configuration?
I will send my config files to you, just let me know what you need.
Also, I will provide any additional info you request.
I really appreciate your help.
Thank you,
Ivo
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Regards,
--
insandotpraja(at)gmaildotcom
