04-24-2010 09:19 AM - edited 03-04-2019 08:16 AM
Hello Guys,
I setup a Multilink connection between 2 router but I can not ping between them. Do I need to provide a clock rate on the Serial interfaces of the Multilink interface or something? Please Advise??? The config for both routers are below.
hostname R1
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
memory-size iomem 15
ip cef
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
interface Multilink1
ip address 172.16.1.1 255.255.255.252
ppp multilink
ppp multilink group 1
!
interface FastEthernet0/0
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/0
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
!
interface FastEthernet0/1
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/1
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
!
interface Serial0/2
no ip address
shutdown
!
interface Serial0/3
no ip address
shutdown
!
!
!
ip http server
no ip http secure-server
!
!
!
!
control-plane
!
!
!
!
!
!
!
!
!
!
line con 0
line aux 0
line vty 0 4
login
!
!
end
hostname R2
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
memory-size iomem 15
ip cef
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
interface Multilink1
ip address 172.16.1.2 255.255.255.252
ppp multilink
ppp multilink group 1
!
interface FastEthernet0/0
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/0
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
!
interface FastEthernet0/1
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/1
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
!
interface Serial0/2
no ip address
shutdown
!
interface Serial0/3
no ip address
shutdown
!
!
!
ip http server
no ip http secure-server
!
!
!
!
control-plane
!
!
!
!
!
!
!
!
!
!
line con 0
line aux 0
line vty 0 4
login
!
!
end
R1#sh int s0/0
Serial0/0 is up, line protocol is down
Hardware is PowerQUICC Serial
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation PPP, LCP REQsent, multilink Closed, loopback not set
Keepalive set (10 sec)
Last input 00:21:20, output 00:00:02, output hang never
Last clearing of "show interface" counters 00:37:40
Input queue: 103/75/152/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/1/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
Available Bandwidth 1158 kilobits/sec
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
225 packets input, 6810 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
479 packets output, 11971 bytes, 0 underruns
0 output errors, 0 collisions, 71 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up
R1#sh int s0/1
Serial0/1 is up, line protocol is down
Hardware is PowerQUICC Serial
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation PPP, LCP Listen, multilink Closed, loopback not set
Keepalive set (10 sec)
Last input 00:21:51, output 00:00:06, output hang never
Last clearing of "show interface" counters 00:38:10
Input queue: 96/75/160/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/1/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
Available Bandwidth 1158 kilobits/sec
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
230 packets input, 6860 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
484 packets output, 12062 bytes, 0 underruns
0 output errors, 0 collisions, 72 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up
R1#sh int multilink 1
Multilink1 is down, line protocol is down
Hardware is multilink group interface
Internet address is 172.16.1.1/30
MTU 1500 bytes, BW 1544 Kbit, DLY 100000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation PPP, LCP Closed, multilink Closed, loopback not set
Keepalive set (10 sec)
DTR is pulsed for 2 seconds on reset
Last input 00:38:40, output never, output hang never
Last clearing of "show interface" counters 00:38:56
Input queue: 28/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
5 packets input, 52 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
34 packets output, 6156 bytes, 0 underruns
0 output errors, 0 collisions, 2 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
R2#sh int s0/0
Serial0/0 is up, line protocol is down
Hardware is PowerQUICC Serial
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation PPP, LCP Listen, multilink Closed, loopback not set
Keepalive set (10 sec)
Last input 00:23:12, output 00:00:04, output hang never
Last clearing of "show interface" counters 00:39:27
Input queue: 110/75/172/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/1/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
Available Bandwidth 1158 kilobits/sec
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
218 packets input, 6178 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
500 packets output, 13100 bytes, 0 underruns
0 output errors, 0 collisions, 75 interface resets
0 output buffer failures, 0 output buffers swapped out
R2#sh int s0/1
Serial0/1 is up, line protocol is down
Hardware is PowerQUICC Serial
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation PPP, LCP REQsent, multilink Closed, loopback not set
Keepalive set (10 sec)
Last input 00:24:24, output 00:00:01, output hang never
Last clearing of "show interface" counters 00:40:37
Input queue: 101/75/190/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/1/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
Available Bandwidth 1158 kilobits/sec
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
222 packets input, 6246 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
513 packets output, 13633 bytes, 0 underruns
0 output errors, 0 collisions, 76 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up
R2#sh int multilink1
Multilink1 is down, line protocol is down
Hardware is multilink group interface
Internet address is 172.16.1.2/30
MTU 1500 bytes, BW 1544 Kbit, DLY 100000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation PPP, LCP Closed, multilink Closed, loopback not set
Keepalive set (10 sec)
DTR is pulsed for 2 seconds on reset
Last input 00:40:52, output never, output hang never
Last clearing of "show interface" counters 00:41:10
Input queue: 28/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
4 packets input, 38 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
34 packets output, 7632 bytes, 0 underruns
0 output errors, 0 collisions, 2 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
0 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up
Solved! Go to Solution.
04-24-2010 09:23 AM
Hi,
If this is a real environment where your routers are connected to an ISP through a WAN, then your routers are DTE devices and therefore don't need a clockrate on the serial interfaces.
If this is a lab setup, then one end has to provide the clock rate which is the DCE.
You can check this with the ''sh controllers serialx/x'' command.
Federico.
04-24-2010 09:50 AM
Check which interface shows you as DCE.
sh controller multilink --> not sure if it works
sh controller serial
The thing is that you should provide the clock rate to the DCE side (being the multilink interface I think, but please verify with the above commands)
Otherwise, set the clock rate on the serial interfaces.
Federico.
04-24-2010 03:07 PM
Hello Ike,
you need to set the clock on the serial interfaces, the command is accepted on the DCE side of the cable and this can be checked with sh controller serial x/y.
A multilink bundle is an OSI layer 2 concept, giving a clock is OSI layer1 for synchronous serials where synchronous means both sides need a common clock to sample the rx stream.
When in a lab with back to back configuration we need to configure one router as OSI Layer 1 DCE with clock rate command command
Hope to help
Giuseppe
04-24-2010 09:23 AM
Hi,
If this is a real environment where your routers are connected to an ISP through a WAN, then your routers are DTE devices and therefore don't need a clockrate on the serial interfaces.
If this is a lab setup, then one end has to provide the clock rate which is the DCE.
You can check this with the ''sh controllers serialx/x'' command.
Federico.
04-24-2010 09:47 AM
This is a lab and I am not sure if I need to put the clock rate on the Multilink interface or the Serial Interface? Which one do I set the Clock rate one?
04-24-2010 09:50 AM
Check which interface shows you as DCE.
sh controller multilink --> not sure if it works
sh controller serial
The thing is that you should provide the clock rate to the DCE side (being the multilink interface I think, but please verify with the above commands)
Otherwise, set the clock rate on the serial interfaces.
Federico.
04-24-2010 03:07 PM
Hello Ike,
you need to set the clock on the serial interfaces, the command is accepted on the DCE side of the cable and this can be checked with sh controller serial x/y.
A multilink bundle is an OSI layer 2 concept, giving a clock is OSI layer1 for synchronous serials where synchronous means both sides need a common clock to sample the rx stream.
When in a lab with back to back configuration we need to configure one router as OSI Layer 1 DCE with clock rate command command
Hope to help
Giuseppe
04-24-2010 05:36 PM
Thank you so much. Everything you said was exactly right. The GNS3 emulation software I was using was faulty. I decided to stop being lazy and connect my real routers and everything I had done worked perfectly.
04-24-2010 05:40 PM
You are correct.
I have noticed that using GNS3, there is no need to specify the clock rate command on the serial DCE interfaces.
On GNS3 you can connect two routers back-to-back and do not mind about the DTE-DCE relationship.
Obviously as you saw, this is not correct with real equipment.
Federico.
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