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FR Switch Config Question 1

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sk391

Technical User
Jun 13, 2007
102
GB
Hello Guy ,
I have created a new post but it is really a carry on from a old post. I got slightly frustrated with my frame relay config not working that I ended up ripping all the cables out and wiping the config from the interfaces and starting again.

I have three router and have config'ed 1 to be a frame relay switch with the following config

interface Serial0
no ip address
encapsulation frame-relay
logging event subif-link-status
logging event dlci-status-change
clock rate 56000
no frame-relay inverse-arp
frame-relay intf-type dce
frame-relay route 111 interface Serial1 222
!
interface Serial1
no ip address
encapsulation frame-relay
clock rate 56000
no frame-relay inverse-arp
frame-relay intf-type dce
frame-relay route 222 interface Serial0 111


The other router has the following

interface Serial0
ip address 172.12.123.1 255.255.255.0
encapsulation frame-relay
!
and the other

interface Serial0/3/0
ip address 172.12.123.2 255.255.255.0
encapsulation frame-relay
no ip route-cache


My understanding of it is that I have configured the frame relay switch with the correct dlcis and then allowed the other routers to use inverse - arp to dynamic work out the dlci and allow the two routers to communication through the frame relay switch.

When I run the command- show frame route on the FR switch I get the following

FrameRelaySwitch#show frame route
Input Intf Input Dlci Output Intf Output Dlci Status
Serial0 111 Serial1 222 active
Serial1 222 Serial0 111 active




I cannot ping from one router to the other through the FR switch.

Does anyone know what I am doing wrong.

I know that the clockrate should be higher than the one set and that I can statically config the routes on the routers which is recommended, but even with this config I should be able to ping , shouldnt I ???

Thanks



 
Also (sorry just trying to get as much information as I can) - I cannot even ping the local interface.
 
I asked you what kind of physical serial interface is in the 2801. I believe that could be an issue. Please verify (VWIC, etc.?).

Burt
 
Hi Burt, sorry i dont know what information you need. I have pulled the card out of the router. Its a serial WIC 1T card. Cant really see anything else on it other than its a Aitera chipset.

Thanks
 
Post a sh diag and sh inventory. Also, switch the routers around to see if the problem follows the 2801. It could be that the hardware in the 2801 is incompatible with that frame setup...the config all looks good...

Burt
 
You're trying to fix something that isn't broken. Put a routing protocol on and the pings will work. What you're seeing is a quirk with serial interfaces and Cisco routers acting as frame-relay switches. When you ping serial links the icmp actually travels up and down the serial link. With the Cisco router as the frame switch in the middle the pings will fail because the serial interface for frame switching makes the icmps unable to reach across the frame switch to the other serial link and the frame switch won't forward at L2 as you expect. If this was a real frame switch the pings would work just fine. Because the cisco router is in the middle here, the pings fail until you get routing working. I have students fight with this a lot. Hopefully, you haven't lost too much sleep with this?
 
Not true in all cases, Tad---I had a 2503 as a frame switch and two 2620's on either end with WIC-1T's with this exact config (where he got it, from me!), and it worked all day long. I just set this up the other day (read the posts here) with one of the 2620's as a frame switch, and a 2503 on one end and a 2620 on the other end. What you are saying is likely the case, but not with the frame switch, but with the serial interface in the 2801---I suspect it is not a WIC-1T, or if it is, the chip is a different manufacturer than what they used to be in the older routers. I am not sure if mine are Aitera or not---will have to pull them out. I posted my configs, and note that there is no routing protocol, nor any static routing/routing of any kind.
I would say that the config looks good and all looks good on paper, especially the status as being active on all DLCI's.
I am not saying that enabling RIP would NOT make it work---it very well might, as I have heard of this issue before---being an instructor, I am sure you have been down this road much more than I---I just know that mine worked with this setup, and no routing protocol.

Burt
 
Burt,

Yep, sometimes it works, sometimes it doesn't. I've done this with 2610s, 2611, 2611XM, 2811, 3640, 2500s. The quirks of the serial interfaces. It's not abnormal to be unable to ping your own directly connected interface with a serial link that shows up/up. I've seen this happen dozens of times with cisco routers as frame switches. I put it under the "job security" heading. In BSCI classes, I use cisco as frame relay for p2p, p2m, main interfaces, sub-interfaces, and so forth. This is a regular issue with frame configured on main interfaces. The posted configs look good but the issue is the "directly connected" interfaces that are trying to be pinged are not really "directly connected".

Tad
 
Hello Guys,

Sorry for the delayed reponse, I came down a heavy flu, got a few days of work though :)- sliver lining and all that.

I have enabled rip on all of the routers including the FR switch with the following commands,

config t
ip routing
router rip
network 172.12.123.0

and tried to ping with no luck ..!

Burt I swaped the 2503 routers around and made the other router the FR switch it gave me the same result - no pings

here is the info that you requested

Router2801#sh diag
Slot 0:
C2801 2FE 4SLOT Mainboard Port adapter, 3 ports
Port adapter is analyzed
Port adapter insertion time unknown
EEPROM contents at hardware discovery:
Chassis MAC Address : 0018.18d5.565e
MAC Address block size : 34
PCB Serial Number : FOC102042C5
Hardware Revision : 6.0
Part Number : 73-8190-06
Board Revision : A0
Top Assy. Part Number : 800-23435-03
Deviation Number : 0
Fab Version : 04
CLEI Code : IPM7P00CRA
RMA Test History : 00
RMA Number : 0-0-0-0
RMA History : 00
Product (FRU) Number : CISCO2801
Version Identifier : V02
Processor type : 86
Chassis Serial Number : FCZ10251030
EEPROM format version 4
EEPROM contents (hex):
0x00: 04 FF C3 06 00 18 18 D5 56 5E 43 00 22 C1 8B 46
0x10: 4F 43 31 30 32 30 34 32 43 35 40 04 1C 41 06 00
0x20: 82 49 1F FE 06 42 41 30 C0 46 03 20 00 5B 8B 03
0x30: 88 00 00 00 00 02 04 C6 8A 49 50 4D 37 50 30 30
0x40: 43 52 41 03 00 81 00 00 00 00 04 00 CB 89 43 49
0x50: 53 43 4F 32 38 30 31 89 56 30 32 20 D9 02 C1 40
0x60: 09 86 C2 8B 46 43 5A 31 30 32 35 31 30 33 30 FF
0x70: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x80: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x90: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0xA0: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0xB0: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0xC0: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0xD0: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0xE0: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0xF0: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x100: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x110: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x120: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x130: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x140: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x150: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x160: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x170: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x180: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x190: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x1A0: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x1B0: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x1C0: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x1D0: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x1E0: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x1F0: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF

WIC/VIC/HWIC Slot 3:
Serial 1T WAN daughter card
Hardware revision 1.0 Board revision B0
Serial number 32327878 Part number 800-01514-02
FRU Part Number WIC-1T=

Test history 0x0 RMA number 00-00-00
Connector type Wan Module
EEPROM format version 1
EEPROM contents (hex):
0x20: 01 02 01 00 01 ED 48 C6 50 05 EA 02 00 00 00 00
0x30: 58 00 00 00 04 04 25 01 FF FF FF FF FF FF FF FF


Router2801#show inventory
NAME: "2801 chassis", DESCR: "2801 chassis, Hw Serial#: 3965508514, Hw Revision: 6.0"
PID: CISCO2801 , VID: V02 , SN: FCZ10251030

NAME: "C2801 Motherboard with 2 Fast Ethernet", DESCR: "C2801 Motherboard with 2 Fast Ethernet"
PID: CISCO2801 , VID: 6.0, SN: FCZ10251030

NAME: "WIC/VIC/HWIC 3", DESCR: "WAN Interface Card - Serial (1T)"
PID: WIC-1T= , VID: 1.0, SN: 32327878

-------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------



RouterB#show inventory
NAME: "2500", DESCR: "2500 chassis, Hw Serial#: 324286466, Hw Revision: N"
PID: , VID: N , SN: 13543802



Any other ideas guys..... please....

Thanks




 
here is an output from debug

Router2801#ping 172.12.123.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.12.123.1, timeout is 2 seconds:

*Nov 22 23:03:57.083: IP: tableid=0, s=172.12.123.2 (local), d=172.12.123.1 (Serial0/3/0), routed via FIB
*Nov 22 23:03:57.083: IP: s=172.12.123.2 (local), d=172.12.123.1 (Serial0/3/0), len 100, sending.
*Nov 22 23:03:59.083: IP: tableid=0, s=172.12.123.2 (local), d=172.12.123.1 (Serial0/3/0), routed via FIB
*Nov 22 23:03:59.083: IP: s=172.12.123.2 (local), d=172.12.123.1 (Serial0/3/0), len 100, sending.
*Nov 22 23:04:01.083: IP: tableid=0, s=172.12.123.2 (local), d=172.12.123.1 (Serial0/3/0), routed via FIB
*Nov 22 23:04:01.083: IP: s=172.12.123.2 (local), d=172.12.123.1 (Serial0/3/0), len 100, sending.
*Nov 22 23:04:03.083: IP: tableid=0, s=172.12.123.2 (local), d=172.12.123.1 (Serial0/3/0), routed via FIB
*Nov 22 23:04:03.083: IP: s=172.12.123.2 (local), d=172.12.123.1 (Serial0/3/0), len 100, sending.
*Nov 22 23:04:05.083: IP: tableid=0, s=172.12.123.2 (local), d=172.12.123.1 (Serial0/3/0), routed via FIB
*Nov 22 23:04:05.083: IP: s=172.12.123.2 (local), d=172.12.123.1 (Serial0/3/0), len 100, sending.
Success rate is 0 percent (0/5)
Router2801#
*Nov 22 23:04:06.323: IP: s=172.12.123.2 (local), d=255.255.255.255 (Serial0/3/0), len 52, sending broad/multicast
*Nov 22 23:04:34.483: IP: s=172.12.123.2 (local), d=255.255.255.255 (Serial0/3/0), len 52, sending broad/multicast
*Nov 22 23:05:00.847: IP: s=172.12.123.2 (local), d=255.255.255.255 (Serial0/3/0), len 52, sending broad/multicast
*Nov 22 23:05:29.143: IP: s=172.12.123.2 (local), d=255.255.255.255 (Serial0/3/0), len 52, sending broad/multicast
*Nov 22 23:05:56.511: IP: s=172.12.123.2 (local), d=255.255.255.255 (Serial0/3/0), len 52, sending broad/multicastu all
Port Statistics for unclassified packets is not turned on.

All possible debugging has been turned off
 
Do you have an extra WIC-1T? If not, I can send you one or two (you pay shipping) just to try them...I would make the 2801 the frame switch. I really think it's the newer hardware not jiving right with the 2500's...
Let me know, or maybe buy a second WIC for that 2801 and make it the frame switch. Or, just try a back-to-back frame config...with only 2 routers...


I didn't even know you could do that until recently!
Tad---had you ever seen a back 2 back frame config like that?

Burt
 
Thanks Burt,
Yeah I agree, for whatever reason as soon as I connect up a FR switch there is something on the 2801 which doesnt want to play. I might have to take you up on your offer of the couple of WIC-1T cards. I am in the UK. Are these cards spare, what price can you do for me. If I can get the two cards into the 2801 I can then make the 2801 router the FR switch or should I just buy another 2503 router and then have all 2503 in my FR setup. I will then loose the power and additional features of the 2901 i.e SDM in my lab set though.

Thanks for all your help on this Burt, Its much appreciatied.

 
I would just buy another 2503. You can definitely use the 2801 for other things---all is not wasted. The 2503 would cost you maybe $20 U.S., maybe what...$10 U.S. for shipping...

Burt
 
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