frame relay

malcybood

I'm following the frame relay techlab instructions exactly and at Step 5 it says verify your progress and line and protocol should be up.

My line is up but protocol is down on both s0/0 and s0/1

It is a lab of 1 x 2620 and 2 x 1721 routers

- I have a 1721 router connected to each of the 2 serial interfaces of the 2600
- I have set the DCE on both serial interfaces of 2600 switch
- I have ensured frame relay encapsulation is on all interfaces on all 3 routers and frame-relay lmi-type ansi on all routers
- I have configured IP addresses and ensured the interfaces on the two 1721's are "no shut"
- ensured fr switch frame-relay switching is on switch

frame switch int config

interface Serial0/0
no ip address
encapsulation frame-relay
frame-relay lmi-type ansi
frame-relay intf-type dce
frame-relay route 122 interface Serial0/1 221
!
interface Serial0/1
no ip address
encapsulation frame-relay
frame-relay lmi-type ansi
frame-relay intf-type dce
frame-relay route 221 interface Serial0/0 122

any ideas?

malcybood

OK so I think I've solved the problem myself but don't really understand how this works.

My setup is

Lab_A(1721 end router)

---

Lab_B(2600 frame_switch)

---

Lab_C(1721 end router)

I initially had the clock rate 56000 set on the 2 serial ports on Lab B to provide clocking. For a laugh I removed the clocking from frame switch Lab_B and put the clocking on the 2 end-point routers serial ports (Lab_A and Lab_C) and pretty much straight away all routers' serial ports changed state from up/down to up/up.

Why does it work when the clocking is on the end-point routers but not when clocking is set on the frame switch serial ports?

Setting the clock rate on the frame switch is how it tells you to do it in the techlab

Thanks
Malc

EdTheLad

The physical link clocking has nothing to do with FR, the port that is used as dce is dependent on the connected serial cable.You can do " show controllers serial 0/0" the output should tell you if a port is dce or dte.Whichever port happens to be dce on the link is where clocking should be configured.