Packet Tracer Static Routing Issues

ukman2003

Hi guys. Trying to figure out this packet tracer which has to do with static routing, and my ip addresses are not working with the exercise. I'm kind of stuck because I have three networks interconnected of routers via serial links. Anyway any help would be appreciated. Just a thumb in the right direction would be great.

Thanks,

Ryan

Here is the address to check it out.
Didn't think I could post it on as an attachment.

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Comments

MentholMoose

The instructions indicate routing is configured wrong on only BRANCH1 and BRANCH2. Thus, the configuration of ISP should be OK, so check it:

ip route 172.16.4.0 255.255.255.0 Serial0/0
ip route 172.16.15.0 255.255.255.0 Serial0/1
ip route 192.168.2.0 255.255.255.252 Serial0/0
ip route 192.168.2.0 255.255.255.252 Serial0/1

There is one route for each branch LAN (172.16.4.0/24 and 172.16.15.0/24), and two routes for the WAN between BRANCH1 and BRANCH2 (192.168.2.0/30). Use this as a baseline for what needs to be on the branch routers.

Here's another pointer. On each branch router, delete the static route, add one route for each of the other LANs, and two routes for the WAN network that can't been seen directly.

As a last resort, here's what I did to fix it (highlight to see it).

BRANCH2#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
BRANCH2(config)#no ip route 0.0.0.0 0.0.0.0 ser 0/0
BRANCH2(config)#ip route 10.10.0.0 255.255.0.0 ser 0/1
BRANCH2(config)#ip route 172.16.4.0 255.255.255.0 ser 0/0
BRANCH2(config)#ip route 192.168.1.4 255.255.255.252 ser 0/1
BRANCH2(config)#ip route 192.168.1.4 255.255.255.252 ser 0/0

BRANCH1#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
BRANCH1(config)#no ip route 0.0.0.0 0.0.0.0 ser 0/1
BRANCH1(config)#ip route 10.10.0.0 255.255.0.0 ser 0/0
BRANCH1(config)#ip route 172.16.15.0 255.255.255.0 ser 0/1
BRANCH1(config)#ip route 192.168.3.8 255.255.255.252 ser 0/0
BRANCH1(config)#ip route 192.168.3.8 255.255.255.252 ser0/1

restrykt

Hi ukman2003!

Please check interfaces (static routes Branch 1 and 2).

Solution
Branch 2 router:
BRANCH2(config)#no ip route 0.0.0.0 0.0.0.0 serial 0/0
(wrong serial interface)

BRANCH2(config)#ip route 0.0.0.0 0.0.0.0 serial 0/1(correct serial interface)

Branch 1 router:

the same situation:

BRANCH1(config)#no ip route 0.0.0.0 0.0.0.0 serial 0/1
then...
BRANCH1(config)#ip route 0.0.0.0 0.0.0.0 serial 0/0

ukman2003

Thanks to both of you guys. I guess I'm going to have to reread this chapter on static routes, seems confusing but I guess it's probably just me. The more I configure I more I understand.

Thanks again,

Ryan

MentholMoose

ukman2003 wrote: »

Thanks to both of you guys. I guess I'm going to have to reread this chapter on static routes, seems confusing but I guess it's probably just me. The more I configure I more I understand.

The problem is that BRANCH1 and BRANCH2 have static default routes pointing at each other. So for example, if BRANCH1 receives a packet to the ISP LAN, it will forward to BRANCH2, since it doesn't have a more specific route for the ISP LAN. When BRANCH2 receives that packet, since it also doesn't have a more specific route to the ISP LAN, it will forward back to BRANCH1! This is a routing loop.