Cisco 2951: setting up and changing a static route.

[roncro]

Hello,

I have two access points, but they are connected to a computer:

AP1 192.168.66.6 (the ipaddr of the computer interface is 192.168.66.1)

AP2 192.168.67.6 (the ipaddr of the computer interface is 192.168.67.1)

The computer's ip "itself" is 192.168.1.112

I used to have it setup with another machine, that worked, but replaced stuff and forgot how I set up the routes on a Cisco 2951

I have to change replace one route on the router I think, and complete another one

here is  the relevant part that "show ip route" shows.

%<

192.168.66.0/24 is variably subnetted, 3 subnets, 2 masks
S 192.168.66.0/25 [1/0] via 192.168.1.110
C 192.168.66.128/25 is directly connected, GigabitEthernet0/1.66
L 192.168.66.131/32 is directly connected, GigabitEthernet0/1.66
192.168.67.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.67.0/24 is directly connected, GigabitEthernet0/1.67
L 192.168.67.131/32 is directly connected, GigabitEthernet0/1.67

%<

How do I change/replace the 192.168.1.110 address, and complete it for the 192.168.67.0 traffic?

thanks,

Ron

[Georg Pauwen]

Hello,

it is difficult to figure out from your description what you are trying to achieve, and what you are asking. Providing a schematic drawing of your topology and visualizing what you are asking could help.

[roncro]

Hello Georg,

what I am trying to do is 'snif' traffic from a wireless device, to figure out a data protocol.   That 's why I connect a wireless access point (AP) via ethernetcable to a computer.  I want the wireless device to connect to wireless as usual, and have the computer route traffic to and from the wireless device, so I can easily see IP traffic.

I used to have a setup that worked, but can't find how I created the entries in the routing table.

What I want is:

replace:

192.168.66.0/24 is variably subnetted, 3 subnets, 2 masks
S 192.168.66.0/25 [1/0] via 192.168.1.110
C 192.168.66.128/25 is directly connected, GigabitEthernet0/1.66
L 192.168.66.131/32 is directly connected, GigabitEthernet0/1.66

with something like:

192.168.66.0/24 is variably subnetted, ? subnets, ? masks
S 192.168.66.0/24 [1/0] via 192.168.1.112
? 192.168.66.0/24 is directly connected, GigabitEthernet0/1.66

basically what I try to accomplish is that anything in the/my network can find the device and vice versa, even with the computer (192.168.1.112).

(hard to draw)

Ron

[roncro]

I think some weirdness is going on.

When I issue a:

ip route 192.168.67.0 255.255.255.128 192.168.1.112

on the router, I see these entries in the routing table:

192.168.67.0/24 is variably subnetted, 3 subnets, 3 masks
C 192.168.67.0/24 is directly connected, GigabitEthernet0/1.67
S 192.168.67.0/25 [1/0] via 192.168.1.112
L 192.168.67.131/32 is directly connected, GigabitEthernet0/1.67

(which works,  but looks clumsy/cluttered)

However, when I issue  a:

ip route 192.168.67.0 255.255.255.0 192.168.1.112   (I want all traffic in the 192.168.67.0 net to go through 192.168.1.112)

the S entry (S 192.168.67.0/25 [1/0] via 192.168.1.112) doesn't show up   well actually, I would expect to see

something like: "S 192.168.67.0/24 [1/0] via 192.168.1.112"

So I am wondering  why the first command I issued "works"  and the second one doesn't?

Ron

[Giuseppe Larosa]

Hello,

from your first post of the IP routing table we see that:

>> C 192.168.67.0/24 is directly connected, GigabitEthernet0/1.67

prefix 192.168.67.0/24 is directly connected to sub-interface gi0/1.67.

You are trying to foul the router to make traffic go via new PC next-hop 192.168.1.112

The trick is to create a set of most specific static routes so you need :

ip route 192.168.67.0 255.255.255.128 192.168.1.112

+

ip route 192.168.67.128 255.255.255.128 192.168.1.112

the static route for 192.168.67.0/24 does not appear in routing table because the connected route has admin distance of 0 and the static route has admin distance of 1.

Be aware of possible routing loops

Hope to help

Giuseppe

[roncro]

correct,  what I want is the router to know that IP traffic for the networks 192.168.66.0 and 192.168.67.0  needs to go through 192.168.1.112

(The old situation I had was for something different, where one piece of equipment was located elsewhere, and yet another on the same 192.168.66.0 ntwork, but attache to  another computer,  that's why the 255/255.255.128 netmask, That old setup is not needed anymore.).

But yes, I want the router "to know" that IP traffic for 192.168.66.0 and 192.168.67.0  needs to go through 192.168.1.112

thanks,

Ron

[balaji.bandi]

just to clarify below route you looking to change to a 112 IP address.

S 192.168.66.0/25 [1/0] via 192.168.1.110

First you need to remove this static route going to 110 and then add static route 112?

Orginal Static Route 66.0/25 Later you adding 67.0/24 is this correct ? or is this your intention?

what is this device having IP address 192.168.1.112 ?  what is the route added for this device ?

[roncro]

correct, however I figured out how to do that,   I just forgot the syntax.

Well ideally,  I want both the 192.168.66.9/24 and 192.168.67.0/24 to be routed to a computer with I address  192.168.1.112

thanks,

Ron

[balaji.bandi]

I agree you going to correct that, again look like a typo here :

192.168.66.9/24 ( that should be 0 i guess) and 192.168.67.0/24

You also need to route back the same subnet from device 192.168.1.112 to back to router to work.

if this windows? route add command should work for you.

[roncro]

that was indeed a typo, sorry about that.

the 192.168.1.112 machine is a linux box.

[balaji.bandi]

If this is Linux box, you need to add route back 192.168.1.112

# route -n   - this will give you exiting static route information

depends on Linux distro check the command syntax for Route add perssitance.

[roncro]

Hello BB,

the distro is RHEL 8, and I already have that part working (routing on the Linux box);  I can ping the Cisco 2951 from the accesspoints through that computer (192.168.1.112, in "the middle"), and vice versa. Routing on the linux box is not an issue at all.

I am just looking to find out what the best/appropriate way is to set up the two routes on the Cisco 2951 (so that I don't have to use those weird netmasks etc, left over from a previous setup/project).

thanks,

Ron

[balaji.bandi]

I am just looking to find out what the best/appropriate way is to set up the two routes on the Cisco 2951 (so that I don't have to use those weird netmasks etc, left over from a previous setup/project).

you can summarise them in to 1 network. not sure what is end goal, orgial post you mentioned routing not working, now you looking different here end of the post.

[roncro]

right, but I want 2 separate networks. 

The endgoal is to have a  decent routing table on the Cisco 2951, right now  I basically just hacked it together. (on the 2951).

Originally it wasn't working, when I tried to  add a route for the whole subnet, but could get it to work with the 255.255.255.128 netmask.

Ron

[balaji.bandi]

you can do /23 to cover 2 subnet or more depends requirement.