Regarding static route

mindzfreak

Hey guys, how do i possible configure a static route from B3 to HQ ? Since hq doesnt have its own network... B1 B2 B3 etc has its own network but HQ doesnt. So how am i going to configure a static route from b3 to hq ?


note: i tried configure a static route 80.80.80.0 255.255.255.252 s1/0 (exit interface) on B3 for it to reach hq. but when i type "show ip route" it doesn't show the static route i just configured.. why why why ??

heres the file... Mock Test Latest.pkt

Any help would definitely be appreciated.. thanks..

CodeBlox

I'm at work and don't have PT here, but is that interface (S1/0 on B3) in an up/up state?

JDMurray

Yeah, when a route doesn't appear in the routing table the first thing to do is a 'show ip interface brief' to check if the interface has an IP address and that it's up/up.

mindzfreak

CodeBlox wrote: »

I'm at work and don't have PT here, but is that interface (S1/0 on B3) in an up/up state?

Yep its up/up state.

mindzfreak

JDMurray wrote: »

Yeah, when a route doesn't appear in the routing table the first thing to do is a 'show ip interface brief' to check if the interface has an IP address and that it's up/up.

yup its up/up state. any idea ??

JDMurray

OK, after actually looking at the pkt file, the directly connected network 80.80.80.0/30 has a lower administrative distance (0) than a static route would have (1), so the static route would serve no purpose. You can make serial1/0 the default gateway using: 'ip route 0.0.0.0 0.0.0.0 serial1/0'.

mella060

mindzfreak wrote: »

Hey guys, how do i possible configure a static route from B3 to HQ ? Since hq doesnt have its own network... B1 B2 B3 etc has its own network but HQ doesnt. So how am i going to configure a static route from b3 to hq ?


note: i tried configure a static route 80.80.80.0 255.255.255.252 s1/0 (exit interface) on B3 for it to reach hq. but when i type "show ip route" it doesn't show the static route i just configured.. why why why ??

But network 80.80.80.0 is directly connected to B3. Just use the next-hop IP address(HQ's s0/0 interface) as the next hop IP to get to the networks beyond the HQ router.

For example...

ip route 10.10.10.0 255.255.255.0 80.80.80.1
ip route 80.80.80.20 255.255.255.252 80.80.80.1
ip route 80.80.80.8 255.255.255.252 80.80.80.1

mindzfreak

JDMurray wrote: »

OK, after actually looking at the pkt file, the directly connected network 80.80.80.0/30 has a lower administrative distance (0) than a static route would have (1), so the static route would serve no purpose. You can make serial1/0 the default gateway using: 'ip route 0.0.0.0 0.0.0.0 serial1/0'.

But my lecturer doesn't allow me to use default route.. he wants me to use static route..

mindzfreak

mella060 wrote: »

But network 80.80.80.0 is directly connected to B3. Just use the next-hop IP address(HQ's s0/0 interface) as the next hop IP to get to the networks beyond the HQ router.

For example...

ip route 10.10.10.0 255.255.255.0 80.80.80.1
ip route 80.80.80.20 255.255.255.252 80.80.80.1
ip route 80.80.80.8 255.255.255.252 80.80.80.1

Only can use next hop..? can i use exit interface instead..?

and btw i tried " Ip route 20.20.20.0 255.255.255.0 80.80.80.1". I can now send my pdu frm b3 to b2 through hq already. thanks but how come my Pc3 still unable to ping Pc2?

mella060

mindzfreak wrote: »

Only can use next hop..? can i use exit interface instead..?

and btw i tried " Ip route 20.20.20.0 255.255.255.0 80.80.80.1". I can now send my pdu frm b3 to b2 through hq already. thanks but how come my Pc3 still unable to ping Pc2?

You can use either the exit interface or the next-hop IP address, it doesn't really matter. But using the next-hop IP address is recommended, especially on links where ARP is used. Using the exit interface means hat the router has to use ARP to locate the address on the other end of the link and more router resources. Anyway, using the next-hop IP address just makes more sense to me (knowing network addresses and where they are etc).

The reason why PC3 is unable to ping PC2 could be that PC2 hasn't got a route back to PC3. Routing is a two-way street. If you have just the static route on B3 pointing to B2 but no static route on B2 pointing back to B3, then packets would be able to get to B2/PC2 but wouldn't know how to get back to B3/PC3. You would need to configure a static route on the B2 router pointing back to B3. For example...

ip route 30.30.30.0 255.255.255.0 80.80.80.6 (B3's serial 0/1 interface)

mindzfreak

mella060 wrote: »

You can use either the exit interface or the next-hop IP address, it doesn't really matter. But using the next-hop IP address is recommended, especially on links where ARP is used. Using the exit interface means hat the router has to use ARP to locate the address on the other end of the link and more router resources. Anyway, using the next-hop IP address just makes more sense to me (knowing network addresses and where they are etc).

The reason why PC3 is unable to ping PC2 could be that PC2 hasn't got a route back to PC3. Routing is a two-way street. If you have just the static route on B3 pointing to B2 but no static route on B2 pointing back to B3, then packets would be able to get to B2/PC2 but wouldn't know how to get back to B3/PC3. You would need to configure a static route on the B2 router pointing back to B3. For example...

ip route 30.30.30.0 255.255.255.0 80.80.80.6 (B3's serial 0/1 interface)

yep i configured a static route of " ip route 30.30.30.0 255.255.255.0 80.80.80.9 (HQ's serial 1/1 interface) on B2 to reach B3. Cuz i've to go through hq to go anywhere.. but no idea why it still unable to ping frm pc3 to pc2..

JDMurray

mindzfreak wrote: »

but no idea why it still unable to ping frm b3 to b2..

I just downloaded a fresh copy of your .pkt file and I get successful pings between B2 and B3. I can ping 80.80.80.6 from B2 and 80.80.80.5 from B3.

Actually, I did change the host names of the routers. I use 'show cdp neighbors' a lot, and having all of the routers named "Router" is no good to me.

mindzfreak

JDMurray wrote: »

I just downloaded a fresh copy of your .pkt file and I get successful pings between B2 and B3. I can ping 80.80.80.6 from B2 and 80.80.80.5 from B3.

Actually, I did change the host names of the routers. I use 'show cdp neighbors' a lot, and having all of the routers named "Router" is no good to me.

Uhm sorry.. i meant i cant ping from pc3 to pc2..

spd3432

I pulled a copy of your file and opened it. I opened console window on PC3 then ran a ping to each interface on the way
30.30.30.1 -- reply
80.80.80.6 -- reply
80.80.80.5 -- reply
20.20.20.1 -- destination host unreachable
I took a glance at the routing tables in B2 and B3 and they only know about routes from their directly connected interfaces. I added a static route entry for the 20.20.20.0/24 network into the routing table on B3 and was able to ping through to PC2.

If I attempt to use the HQ interface (adding default route) for the B2 branch, then pings fail since the HQ router doesn't forward the packets correctly because you've put static routes for the 10, 30, and 40 networks all coming out of S1/0 instead of the correct interfaces. 10 should be S1/0, 20 is correct as S1/1, 30 should be S0/0, and 40 should be S0/1.

JDMurray

mindzfreak wrote: »

Uhm sorry.. i meant i cant ping from pc3 to pc2..

On B3 you can add a default gateway to s0/1, or a route to 20.20.20.0/24 to s0/1.

mindzfreak

JDMurray wrote: »

On B3 you can add a default gateway to s0/1, or a route to 20.20.20.0/24 to s0/1.

That i know. but the problem is, my lecturer wants my b3 to go through hq to go anywhere.. so i configured " ip route 20.20.20.0 255.255.255.0 80.80.80.1 (HQ s0/0 interface) for b3 to reach b2 through Hq and not directly to b2. My pdu can now be send from pc3 to pc2 through HQ. But problem now is i still cant ping from pc3 to pc2 through hq.. any idea..?

spd3432

I took a little deeper look at your configuration. I took paper and pencil, diagrammed your topology, checked the interfaces and found some very interesting items.
HQ - S1/1 80.80.80.9
B3 - S0/0 80.80.80.9

B2 - S1/0 80.80.80.10
B4 - S0/0 80.80.80.10

HQ - S0/0 80.80.80.1
B1 - S0/0 80.80.80.1

B2 - S0/0 80.80.80.2
B3 - S1/0 80.80.80.2

Static routing tables on HQ --
10.10.10.x use S1/0 -- that is the correct interface
20.20.20.x use S1/1 -- that is the correct interface
30.30.30.x use S1/0 -- the correct interface should be S0/0
40.40.40.x use S1/0 -- the correct interface should be S0/1

It's been a while since I've worked with routers, but I don't see any default routes in the branch routers, how is B1 supposed to know to send packets for the VLANs in the other branch offices through HQ if you don't have the interface for HQ set as the gateway of last resort?

Get rid of the duplicate IP addresses between links B1 <--> B2 and HQ <--> B3 & HQ <--> B2 and B3 <--> B4. Fix the outbound interfaces on the HQ static routing entries. Add the outbound to HQ interface as the default gateway on the branch routers and see if you can ping.