Is anyone running a 3620 router, with an NM-2FE2W carrier module, with a WIC-2T using Frame-Relay?
I have been asked to look at a possible hardware issue with these components, and have seen one of the serial ports up, and the other bouncing.
The circuits have been tested and are fine.
I have put the router in a lab using HDLC encapsulation, and can get both serial ports to work. I have even put a WIC-1T in the spare slot to ensure that the WIC-2T is not faulty. All three interfaces work.
When I configure the router for Frame-Relay encapsulation, the WIC-1T interface is fine and traffic passes over the link.
The WIC-2T interface comes up when enabled, but drops after 30 seconds (3 keepalives).
By debugging the Frame-Relay LMI I see that the router is not receiving LMI status messages from the FR switch. The FR switch (another 3620) is sending the messages, and is receiving enquiries from the DTE.
eg (taken before the DTE drops the link)
00:16:14: Serial0/0(out): StEnq, myseq 3, yourseen 0, DTE up
00:16:14: datagramstart = 0x2B014D4, datagramsize = 13
00:16:14: FR encap = 0xFCF10309
00:16:14: 00 75 01 01 00 03 02 03 00
00:16:14:
00:16:24: Serial0/0(out): StEnq, myseq 4, yourseen 0, DTE up
00:16:24: datagramstart = 0x2B01614, datagramsize = 13
00:16:24: FR encap = 0xFCF10309
00:16:24: 00 75 01 01 00 03 02 04 00
00:16:24:
On the WIC-1T interface the same debug shows the correct sequence...
00:07:22: Serial0/2(out): StEnq, myseq 43, yourseen 42, DTE up
00:07:22: datagramstart = 0x2D092B4, datagramsize = 13
00:07:22: FR encap = 0xFCF10309
00:07:22: 00 75 01 01 01 03 02 2B 2A
00:07:22:
The config is very straight forward ...
DTE config excerpt ...
interface Serial0/0
no ip address
encapsulation frame-relay
no fair-queue
clockrate 2000000
!
interface Serial0/0.100 point-to-point
ip address 172.21.22.2 255.255.255.252
frame-relay interface-dlci 100
!
interface Serial0/0.101 point-to-point
ip address 172.21.22.106 255.255.255.252
frame-relay interface-dlci 101
DCE config excerpt ...
frame-relay switching
!
interface Serial0/1
no ip address
encapsulation frame-relay
clockrate 2000000
frame-relay intf-type dce
!
interface Serial0/1.100 point-to-point
ip address 172.21.22.1 255.255.255.252
frame-relay interface-dlci 100
!
interface Serial0/1.101 point-to-point
ip address 172.21.22.105 255.255.255.252
frame-relay interface-dlci 101
The LMI type is cisco (I have tried ansi and q933a) and the FR encap is defaulted to cisco (I have tried IETF).
I have tried a number of different IOS versions and feature sets (12.1T, 12.2, 12.2T / IP and IP plus)
I have completely swapped all the hardware for new equipment, and have used from 32MB DRAM to 64MB DRAM, and from 8MB Flash to 24MB Flash dependent on IOS version.
Has anyone else experienced this, or have any advice?
Why should this work for HDLC, but not FR?
