08-09-2008 11:47 AM - edited 03-03-2019 11:05 PM
Hi there,
Got this routing problem in my lab at home and looking for some advice.
I have 3 routers R1 > R2 > R3. R3 is the end router advertising a default root via RIP v2. All 3 routers are running classless routing.
All routing between subnets is working a treat. Below is an extract of the routing tables from each router.
R1
Gateway of last resort is 10.151.2.1 to network 0.0.0.0
10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
R 10.149.3.0/24 [120/2] via 10.151.2.1, 00:00:21, Serial0/0
R 10.149.2.0/24 [120/2] via 10.151.2.1, 00:00:21, Serial0/0
R 10.150.2.0/30 [120/1] via 10.151.2.1, 00:00:21, Serial0/0
C 10.151.2.0/30 is directly connected, Serial0/0
C 192.168.1.0/24 is directly connected, FastEthernet0/0
R* 0.0.0.0/0 [120/2] via 10.151.2.1, 00:00:21, Serial0/0
R2
Router with up/up interface 10.151.2.1
Gateway of last resort is 10.150.2.2 to network 0.0.0.0
10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
R 10.149.3.0/24 [120/1] via 10.150.2.2, 00:00:27, Serial0
R 10.149.2.0/24 [120/1] via 10.150.2.2, 00:00:27, Serial0
C 10.150.2.0/30 is directly connected, Serial0
C 10.151.2.0/30 is directly connected, Serial1
R 192.168.1.0/24 [120/1] via 10.151.2.2, 00:00:27, Serial1
R* 0.0.0.0/0 [120/1] via 10.150.2.2, 00:00:27, Serial0
R3
Router with up/up interface 10.150.2.2
Gateway of last resort is 0.0.0.0 to network 0.0.0.0
86.0.0.0/30 is subnetted, 1 subnets
C 86.54.12.56 is directly connected, Ethernet0
10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
C 10.149.3.0/24 is directly connected, Loopback2
C 10.149.2.0/24 is directly connected, Loopback1
C 10.150.2.0/30 is directly connected, Serial0
R 10.151.2.0/30 [120/1] via 10.150.2.1, 00:00:07, Serial0
R 192.168.1.0/24 [120/2] via 10.150.2.1, 00:00:07, Serial0
S* 0.0.0.0/0 is directly connected, Ethernet0
If i run a 'show ip route 25.25.25.5 from any router i receive a message stating the network is not in the table, which i dont understand, i thought the default route takes care of this? depending on classful/classless routing.
Also, if i run a tracert www.cisco.com from a host off R1 i see routes the packet is taking. See below.
1 <1 ms <1 ms <1 ms 192.168.1.1
2 23 ms 23 ms 23 ms 10.151.2.1
3 47 ms 44 ms 44 ms 10.150.2.2
So how come, when using a show ip route from the IOS it returns - network not in table even though the packet is being routed?
Any advice would be great!
Cheers,
Garry
Solved! Go to Solution.
08-09-2008 12:55 PM
Hello Garry,
what you see is normal: when you do sh ip route 25.25.25.5 the router will look to find a match in the ip routing table.
If there isn't a prefix in the routing table the answer is the one you see.
With a single notable execption: the net 0.0.0.0/0 is never considered a match for a prefix.
By the way, sh ip route 0.0.0.0 provides a result only when a default route is present in the routing table.
I usually do this way
sh ip route x.x.x.x
if the answer is not in table I check if there is a default with
sh ip route 0.0.0.0
Hope to help
Giuseppe
08-09-2008 12:55 PM
Hello Garry,
what you see is normal: when you do sh ip route 25.25.25.5 the router will look to find a match in the ip routing table.
If there isn't a prefix in the routing table the answer is the one you see.
With a single notable execption: the net 0.0.0.0/0 is never considered a match for a prefix.
By the way, sh ip route 0.0.0.0 provides a result only when a default route is present in the routing table.
I usually do this way
sh ip route x.x.x.x
if the answer is not in table I check if there is a default with
sh ip route 0.0.0.0
Hope to help
Giuseppe
08-09-2008 11:29 PM
Giuseppe, this is great! exactly what i was looking for. thanks!
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