[CentOS] Network routes

[Jason Pyeron]

> -----Original Message-----
> From: centos-bounces at centos.org 
> [mailto:centos-bounces at centos.org] On Behalf Of Les Mikesell
> Sent: Tuesday, January 29, 2008 18:25
> To: CentOS mailing list
> Subject: Re: [CentOS] Network routes
> 
> 
> You probably want to remove the default route through NE.TW.KB.1 and add 
> routes for the specific networks that you can reach though 
> it.  Normally  routing is done toward a destination network/address
without 
> regard to the route of a packet you might be replying to.  As for an 
> 'outage', how do you define/detect the outage?  Normally if you want
routes to be 
> determined dynamically you would set up a routing protocol with the 
> next-hop routers - or for simple failover the alternative gateway 
> routers might be configured via hsrp or vrrp to have a floating IP 
> address that the rest of the LAN uses as the default gateway address.
> 

Droping the failover requirements, pings still do not respond off the local
subnet.

[root at host20 ~]# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use
Iface
NET.WOR.KA.0    0.0.0.0         255.255.255.0   U     0      0        0 eth1
192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 eth0
NE.TW.RKB.0     0.0.0.0         255.255.255.0   U     0      0        0 eth0
169.254.0.0     0.0.0.0         255.255.0.0     U     0      0        0 eth1
0.0.0.0         NET.WOR.KA.1    0.0.0.0         UG    0      0        0 eth1


[root at host20 ~]# tcpdump -n 'icmp[0] = 8 or icmp[0] = 0'
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
20:27:02.789177 IP 192.168.1.114 > 192.168.1.20: icmp 64: echo request seq 0
20:27:02.789277 IP 192.168.1.20 > 192.168.1.114: icmp 64: echo reply seq 0
20:27:03.786470 IP 192.168.1.114 > 192.168.1.20: icmp 64: echo request seq
256
20:27:03.786509 IP 192.168.1.20 > 192.168.1.114: icmp 64: echo reply seq 256
20:27:04.778574 IP 192.168.1.114 > 192.168.1.20: icmp 64: echo request seq
512
20:27:04.778612 IP 192.168.1.20 > 192.168.1.114: icmp 64: echo reply seq 512
20:27:05.778262 IP 192.168.1.114 > 192.168.1.20: icmp 64: echo request seq
768
20:27:05.778299 IP 192.168.1.20 > 192.168.1.114: icmp 64: echo reply seq 768
20:27:08.032006 IP CO.MC.A.ST > NE.TW.RKB.IP1: icmp 64: echo request seq 0
20:27:09.026055 IP CO.MC.A.ST > NE.TW.RKB.IP1: icmp 64: echo request seq 256
20:27:10.032333 IP CO.MC.A.ST > NE.TW.RKB.IP1: icmp 64: echo request seq 512
20:27:11.025881 IP CO.MC.A.ST > NE.TW.RKB.IP1: icmp 64: echo request seq 768
20:27:13.022155 IP CO.MC.A.ST > NE.TW.RKB.IP1: icmp 64: echo request seq
1280

13 packets captured
13 packets received by filter
0 packets dropped by kernel

Why are there no replies being sent?


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