Frame relay back to back configuration.

[thisisshanky]

Hi,

I tried configuring frame relay back to back config as per Cisco docs. But i am not able to ping either ends. Any comments.

Refer this site for the configs. http://www.cisco.com/warp/public/125/frbacktoback.html

Shanky

[svermill]

Did you add static routes or set up a routing protocol?

I prefer this method where you set one router us as a FR switch so that LMI is implemented:

http://www.cisco.com/warp/public/125/frbacktoback_hybrid.html

[thisisshanky]

thanks for the reply!

i saw that link too.

Here is the scenario. A connected to B using serial cable. Configs are as before. A has 10.1.1.1 /24 and B has 10.1.1.2/24. A cannot ping B and vice versa. To ping this, you dont need a routing protocol.

The interface is up, as keepalive is not set. Everything works according to what the webpage says, But i cannot ping.

[svermill]

Yes, my initial question wasn't very well thought out or at least very well worded. I am curious if you went with the subinterfaces and dlci statements as in the example or did you go with major interfaces and map statements. I am just wondering how (if) inarp works across this test configuration. So although I know it sounds silly, I just wonder what would happen if you added a host route to the opposite end interface out of the local interface. Or something along those lines.

Again, I normally use the hybrid config and I seem to recall that inarp does it's thing and thus no problems pinging interfaces.

[svermill]

Since it only took a few minutes, I went ahead and set this up in my lab. It worked fine with subinterfaces and the dlci statement without any additional config. I also did it using major interfaces. It also worked fine as long as the manual 'frame map ip blah blah' statements were in place.

I tried adding the 'frame interface-dlci' statement that you would normally use on a subinterface to the major interface instead of using map statements. That failed until I added a host route to the other side of the connection.

[thisisshanky]

HI,

i had set the same setup as in the webpage, as well as on main interface. i tried both configs. But i am not able to ping. i gave a debug frame packet command, and it shows me that packets were sent out but no reply is obtained.

shanky

[ghawas]

Guys,

You need to make sure that the DCE router has a clock rate configured. The serial port and line protocol will indicate that they are up even without the clock rate since Keepalive is disabled.

You will not be able to ping each ends if the clock rate is not set at the DCE end

Ahmed Al-Ghawas

CCIE (Written)

[thisisshanky]

Hi Ahmed,

I double checked that too. The routers are two 1600s, the serial cable is attached s0 to s0 and dce end is configured with clock rate of 56k.

still its not pinging.

shanky

[echallen]

Hi Ahmed,

Did you do a show controllers on each of the interfaces to verify that cables were connected properly?

EC

[thisisshanky]

Ok, here you go,

I was running ipsec between these 2 routers. so u know now that the same setup is working perfect.

Now i write erased the routers. and configured the setup for this example.

Its not working still.

shanky

[thisisshanky]

Here i paste the config of the two routers.

R1

int s0

ip address 10.1.1.1 255.255.255.0

encapsulation frame-relay

no keepalive

frame-relay map ip 10.1.1.2 100

frame-relay interface-dlci 100

R2

int s0

ip address 10.1.1.2 255.255.255.0

encapsulation frame-relay

no keepalive

clock rate 56000

frame-relay map ip 10.1.1.1 101

frame-relay interface-dlci 101

i checked the cable, its working fine, without framerelay encapsulation, link is coming up.

now tell me!

shanky

[svermill]

Your dlci values need to be the same. Remember that LMI is not in force in this configuration. So the directly, non-switched routers need to reference the same dlci. Try that and then tell us!

[thisisshanky]

HI,

thanx for response...

i missed out that part in the configs.

well thanx to all for time spend in this discussion, but it was really helpful.

shanky

[thisisshanky]

Sorry i forgot to tell one thing. The scenario worked out fine.

thanks

Shanky