06-08-2010 01:19 PM - edited 03-06-2019 11:29 AM
Why is it that when pinging from the f0/0 (10.1.55.1) to a host (10.1.55.38) the ICMP reply are using RIB? I have CEF enabled and I can understand why the icmp packet destined for .38 would use the FIB table. - Why would the responses use the RIB?
Jun 8 16:03:18.995: IP: tableid=0, s=10.1.55.1 (local), d=10.1.55.38 (FastEthernet0/0), routed via FIB
Jun 8 16:03:18.995: IP: s=10.1.55.1 (local), d=10.1.55.38 (FastEthernet0/0), len 100, sending
Jun 8 16:03:18.995: ICMP type=8, code=0
Jun 8 16:03:18.999: IP: tableid=0, s=10.1.55.38 (FastEthernet0/0), d=10.1.55.1 (FastEthernet0/0), routed via RIB
Jun 8 16:03:18.999: IP: s=10.1.55.38 (FastEthernet0/0), d=10.1.55.1 (FastEthernet0/0), len 100, rcvd 3
Jun 8 16:03:18.999: ICMP type=0, code=0
Jun 8 16:03:18.999: ICMP: echo reply rcvd, src 10.1.55.38, dst 10.1.55.1
Jun 8 16:03:18.999: IP: tableid=0, s=10.1.55.1 (local), d=10.1.55.38 (FastEthernet0/0), routed via FIB
Jun 8 16:03:18.999: IP: s=10.1.55.1 (local), d=10.1.55.38 (FastEthernet0/0), len 100, sending
Jun 8 16:03:18.999: ICMP type=8, code=0
rtr-culpeper#sh ip interface
FastEthernet0/0 is up, line protocol is up
Internet address is 10.1.55.1/24
Broadcast address is 255.255.255.255
Address determined by non-volatile memory
MTU is 1500 bytes
Helper address is not set
Directed broadcast forwarding is disabled
Secondary address 10.200.20.73/30
Multicast reserved groups joined: 224.0.0.10
Outgoing access list is not set
Inbound access list is not set
Proxy ARP is enabled
Local Proxy ARP is disabled
Security level is default
Split horizon is enabled
ICMP redirects are always sent
ICMP unreachables are always sent
ICMP mask replies are never sent
IP fast switching is enabled
IP fast switching on the same interface is disabled
IP Flow switching is enabled
IP CEF switching is enabled
IP CEF Flow Fast switching turbo vector
IP multicast fast switching is enabled
IP multicast distributed fast switching is disabled
IP route-cache flags are Fast, Flow cache, CEF, Full Flow
Router Discovery is disabled
IP output packet accounting is enabled
IP access violation accounting is disabled, system threshold is 512
TCP/IP header compression is disabled
RTP/IP header compression is disabled
Policy routing is disabled
Network address translation is disabled
BGP Policy Mapping is disabled
WCCP Redirect outbound is disabled
WCCP Redirect inbound is disabled
WCCP Redirect exclude is disabled
Solved! Go to Solution.
06-08-2010 01:46 PM
The destination is not local.
06-08-2010 01:38 PM
Hi,
It's not using the FIB because it doesnt have to forward the packet to another host. The router is the destination. The FIB is a Mtrie leaf data structure. Each leaf points to an entry in the adjacency table.
06-08-2010 01:40 PM
And...Look's like a bad default gateway on the host...try enabling proxy arp just to test it.
06-08-2010 01:42 PM
Thanks Dominic and the gateway was the first thing I checked and it's set correctly!!!!
06-08-2010 01:44 PM
Jun 8 16:03:18.999: ICMP: echo reply rcvd, src 10.1.55.38, dst 10.1.55.1
Jun 8 16:03:18.999: IP: tableid=0, s=10.1.55.1 (local), d=10.1.55.38 (FastEthernet0/0), routed via FIB
Why does it say 'FIB' here?
06-08-2010 01:46 PM
The destination is not local.
06-08-2010 01:48 PM
Got it and thanks, D.
06-08-2010 01:49 PM
Is the netmask of the client correct?
I would realy try proxy-arp if I was you, over the years, I've stumble over a few host with bad network implementation.
06-08-2010 01:52 PM
I'm going to try proxy-arp now. The all ip information is correct. 10.1.55.38/24 gw is .1... It was working early today and then the location had a power failure.
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