thanks for the reply john really appreciated but when I tried changing back to default setting of keepalive my protocol went down:

R1#ping 172.16.10.2

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 172.16.10.2, timeout is 2 seconds:

.....

Success rate is 0 percent (0/5)

R1#conf t

Enter configuration commands, one per line. End with CNTL/Z.

R1(config)#int s0

R1(config-if)#keepalive 10

R1(config-if)#^Z

R1#wr

Building configuration...

[OK]

R1#sh ip int brief

Interface IP-Address OK? Method Status Protocol

BRI0 unassigned YES NVRAM administratively down down

BRI0:1 unassigned YES unset administratively down down

BRI0:2 unassigned YES unset administratively down down

Ethernet0 192.168.1.1 YES NVRAM up up

Serial0 172.16.10.1 YES NVRAM up down

Serial1 172.16.11.1 YES NVRAM down down

R1#

here's the new config:

R1#sh run

Building configuration...

Current configuration : 797 bytes

!

version 12.1

no service single-slot-reload-enable

service timestamps debug uptime

service timestamps log uptime

service password-encryption

!

hostname R1

!

boot bootstrap tftp c2500-i-l.121-27b_4.bin 255.255.255.255

enable secret 5 $1$mdza$1Tcbw2xIy1KQ8XQy1mcHk0

enable password 7 05000F0433

!

!

!

!

!

ip subnet-zero

no ip domain-lookup

!

!

!

!

interface Ethernet0

ip address 192.168.1.1 255.255.255.0

!

interface Serial0

ip address 172.16.10.1 255.255.255.0

clockrate 64000

!

interface Serial1

ip address 172.16.11.1 255.255.255.0

no keepalive

clockrate 64000

!

interface BRI0

no ip address

no ip route-cache

no ip mroute-cache

shutdown

!

ip classless

no ip http server

!

!

line con 0

password 7 094A420C01

login

line aux 0

line vty 0 4

password 7 00021F031C50020D1D

login

!

end

R1#

Could you post R2 config ?

Router2 Config:

R2#sh run

Building configuration...

Current configuration : 784 bytes

!

version 12.3

service timestamps debug datetime msec

service timestamps log datetime msec

service password-encryption

service udp-small-servers

service tcp-small-servers

!

hostname R2

!

boot-start-marker

boot-end-marker

!

enable secret 5 $1$i3C0$BjvjJfuGppy/dhNIt/JKf1

enable password 7 01180F0F49

!

no aaa new-model

ip subnet-zero

!

!

!

!

!

interface Ethernet0

ip address 192.168.1.2 255.255.255.0

!

interface Serial0

ip address 172.16.10.2 255.255.255.0

!

interface Serial1

ip address 172.16.11.2 255.255.255.0

no keepalive

!

interface BRI0

no ip address

encapsulation hdlc

no ip route-cache

shutdown

!

no ip http server

ip classless

!

!

!

!

line con 0

password 7 14111E0E14

login

line aux 0

transport input all

line vty 0 4

password 7 094A420C010E1E1919

login

!

end

R2#

More than likely it's not recognizing the cable between the two devices. The no keepalive "hides" the problem. :)

Can you post "sh int s0" from both routers? I'm assuming that your S0 is also configured on the other router, and can you post the other routers config as well?

John

R1#

R1#

R1#

R1#sh int s0

Serial0 is up, line protocol is down

Hardware is HD64570

Internet address is 172.16.10.1/24

MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation HDLC, loopback not set

Keepalive set (10 sec)

Last input never, output 00:00:03, output hang never

Last clearing of "show interface" counters never

Input queue: 0/75/0/0 (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)

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

0 packets input, 0 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

110 packets output, 12414 bytes, 0 underruns

0 output errors, 0 collisions, 25 interface resets

0 output buffer failures, 0 output buffers swapped out

60 carrier transitions

DCD=up DSR=up DTR=up RTS=up CTS=up

R1#

R2#

R2#

R2#sh int s0

Serial0 is up, line protocol is down

Hardware is HD64570

Internet address is 172.16.10.2/24

MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation HDLC, loopback not set

Keepalive set (10 sec)

Last input never, output 00:00:00, output hang never

Last clearing of "show interface" counters never

Input queue: 0/75/0/0 (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

0 packets input, 0 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

122 packets output, 11686 bytes, 0 underruns

0 output errors, 0 collisions, 30 interface resets

0 output buffer failures, 0 output buffers swapped out

50 carrier transitions

DCD=up DSR=up DTR=up RTS=up CTS=up

R2#

yeah this is weird but when I put the no keepalive command the interfaces will show Up Up. lolz.. this is weird though.

Anyone expertz experienced this kind of drama before?

Hello Paul,

check cabling you may have connected the ports R1:ser0 to R2:ser1 and r1:ser1 to r2:ser0

this could explain why enabling keepalive on ser0s you see them going down because ser1s still have no keepalive on them

cable type should be correct :

DCD=up DSR=up DTR=up RTS=up CTS=up

Hope to help

Giuseppe

when I put all the keepalives back all of my serial interfaces went down:

R2#sh int s0

Serial0 is down, line protocol is down

Hardware is HD64570

Internet address is 172.16.10.2/24

MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation HDLC, loopback not set

Keepalive set (10 sec)

Last input never, output 00:00:56, output hang never

Last clearing of "show interface" counters never

Input queue: 0/75/0/0 (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

0 packets input, 0 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

215 packets output, 13732 bytes, 0 underruns

0 output errors, 0 collisions, 63 interface resets

0 output buffer failures, 0 output buffers swapped out

113 carrier transitions

DCD=down DSR=down DTR=down RTS=down CTS=down

R2#sh int s1

Serial1 is down, line protocol is down

Hardware is HD64570

Internet address is 172.16.11.2/24

MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation HDLC, loopback not set

Keepalive set (10 sec)

Last input never, output never, output hang never

Last clearing of "show interface" counters never

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: weighted fair

Output queue: 0/1000/64/0 (size/max total/threshold/drops)

Conversations 0/0/256 (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

0 packets input, 0 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

0 packets output, 0 bytes, 0 underruns

0 output errors, 0 collisions, 1 interface resets

0 output buffer failures, 0 output buffers swapped out

0 carrier transitions

DCD=up DSR=up DTR=down RTS=down CTS=up

R2#sh ip int brief

Interface IP-Address OK? Method Status Protocol

BRI0 unassigned YES NVRAM administratively down down

BRI0:1 unassigned YES unset administratively down down

BRI0:2 unassigned YES unset administratively down down

Ethernet0 192.168.1.2 YES NVRAM up up

Serial0 172.16.10.2 YES NVRAM down down

Serial1 172.16.11.2 YES NVRAM down down

R2#

R1#sh int s0

Serial0 is down, line protocol is down

Hardware is HD64570

Internet address is 172.16.10.1/24

MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation HDLC, loopback not set

Keepalive set (10 sec)

Last input never, output 00:04:27, output hang never

Last clearing of "show interface" counters never

Input queue: 0/75/0/0 (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)

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

0 packets input, 0 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

206 packets output, 14526 bytes, 0 underruns

0 output errors, 0 collisions, 65 interface resets

0 output buffer failures, 0 output buffers swapped out

125 carrier transitions

DCD=up DSR=up DTR=down RTS=down CTS=up

R1#sh int s1

Serial1 is down, line protocol is down

Hardware is HD64570

Internet address is 172.16.11.1/24

MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation HDLC, loopback not set

Keepalive set (10 sec)

Last input never, output never, output hang never

Last clearing of "show interface" counters never

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: weighted fair

Output queue: 0/1000/64/0 (size/max total/threshold/drops)

Conversations 0/0/256 (active/max active/max total)

Reserved Conversations 0/0 (allocated/max allocated)

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

0 packets input, 0 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

0 packets output, 0 bytes, 0 underruns

0 output errors, 0 collisions, 1 interface resets

0 output buffer failures, 0 output buffers swapped out

0 carrier transitions

DCD=down DSR=down DTR=down RTS=down CTS=down

R1#sh ip int brief

Interface IP-Address OK? Method Status Protocol

BRI0 unassigned YES NVRAM administratively down down

BRI0:1 unassigned YES unset administratively down down

BRI0:2 unassigned YES unset administratively down down

Ethernet0 192.168.1.1 YES NVRAM up up

Serial0 172.16.10.1 YES NVRAM down down

Serial1 172.16.11.1 YES NVRAM down down

R1#

No keepalives on the interface isn't causing your issue though. Have you tried moving the same cable to S1 interface to see if you exhibit the same issue? Giuseppe is correct in that maybe you have the cable crossed from S0 to S1 on the other router?

John

Hi John,

The cable connected only from R1 S0 to R2 S0 but I tried connecting from R1 S0 to R2 S1 and change R2 S1's Ip Address but still can't ping at all the status down down

And I tried put all the settings back from where it was like no keepalive, serial cable connected from r1s0 to r2s0, put all together back even the IP Address, sh ip int brief:

R2#sh ip int brief

Interface IP-Address OK? Method Status Protocol

BRI0 unassigned YES NVRAM administratively down down

BRI0:1 unassigned YES unset administratively down down

BRI0:2 unassigned YES unset administratively down down

Ethernet0 192.168.1.2 YES NVRAM up up

Serial0 172.16.10.2 YES NVRAM up up

Serial1 172.16.11.2 YES manual down down

R2#ping 172.16.10.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 172.16.10.1, timeout is 2 seconds:

.....

Success rate is 0 percent (0/5)

R2#

Still no luck.. c",)