Hello all: I have two Cisco 4000-M routers in my home lab with two serial ports on each. S0 on Router 1 is connected to S0 on Router 2. S1 on Router 1 is connected to S1 on Router 2. The problem is that the S1 to S1 link comes up and stays up. The S0 to S0 link comes up but goes down in a few seconds. It keeps going up and down in this way repeatedly. Could someone please shed some light?
The routers are connected using DCE to DTE cross connect cables. The DCE ends of both connections are on Router 2 and it providing clocking at 56000 bits per second. Encapsulation is HDLC although I have tried PPP with the same problem. I have also tried changing the default keepalive settings on both end on the S0 to SO link. The IOS is 12.1(12) on both. I have tried 12.1(10) with the same results. I have also tried changing the end where the clocking is provided with no success. I have switched cables and serial interface modules but the problem remains. Config on Router 1: interface Serial0 ip address 1.1.1.1 255.255.255.0 ! interface Serial1 ip address 2.2.2.1 255.255.255.0 ! Log entries on Router 1: Feb 25 17:59:41: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to up Feb 25 18:00:01: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to down Feb 25 18:00:11: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to up Feb 25 18:00:31: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to down SH IP INTERFACE BRIEF on Router 1: Interface IP-Address OK? Method Status Protocol Serial0 1.1.1.1 YES NVRAM up down Serial1 2.2.2.1 YES NVRAM up up R1#sh control serial 0 MK5 unit 0, NIM slot 1, NIM type code 7, NIM version 1 idb = 0x619DACBC, driver structure at 0x619E10C0, regaddr = 0x3C100300 IB at 0x400FB1CC: mode=0x0108, local_addr=0, remote_addr=0 N1=1524, N2=1, scaler=100, T1=1000, T3=2000, TP=1 buffer size 1524 DTE V.35 serial cable attached DEBUG SERIAL INTERFACE on Router 1 Feb 25 18:26:31: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to down Feb 25 18:26:40: MK5(0): New serial state = 0xA104 Feb 25 18:26:40: MK5(0): DCD is up. Feb 25 18:26:40: Serial0: HDLC myseq 16, mineseen 0*, yourseen 16, line up Feb 25 18:26:41: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to up Feb 25 18:26:50: MK5(0): New serial state = 0x8104 Feb 25 18:26:50: MK5(0): DCD is up. Feb 25 18:26:50: MK5(0): Deasserting DTR Feb 25 18:26:50: MK5(0): Deasserting DTR Feb 25 18:26:50: MK5(0): Reset Feb 25 18:26:50: MK5(0): Asserting DTR Feb 25 18:26:50: MK5(0): Deasserting LTST Feb 25 18:26:50: MK5(0): New serial state = 0xA105 Feb 25 18:26:50: MK5(0): DCD is up. Feb 25 18:26:50: Serial0: HDLC myseq 17, mineseen 0*, yourseen 17, line up Feb 25 18:26:56: MK5(0): New serial state = 0xA124 Feb 25 18:26:56: MK5(0): DCD is up. Feb 25 18:26:56: MK5(0): New serial state = 0xA13C Feb 25 18:26:56: MK5(0): DCD is down. Feb 25 18:26:56: MK5(0): New serial state = 0xA134 Feb 25 18:26:56: MK5(0): DCD is down. Feb 25 18:26:56: MK5(0): New serial state = 0xA114 Feb 25 18:26:56: MK5(0): DCD is down. Feb 25 18:26:56: MK5(0): New serial state = 0xA104 Feb 25 18:26:56: MK5(0): DCD is up. Feb 25 18:27:00: MK5(0): New serial state = 0xA104 Feb 25 18:27:00: MK5(0): DCD is up. Feb 25 18:27:00: MK5(0): Deasserting DTR Feb 25 18:27:00: MK5(0): Deasserting DTR Feb 25 18:27:00: MK5(0): Reset Feb 25 18:27:00: MK5(0): Asserting DTR Feb 25 18:27:00: MK5(0): Deasserting LTST Feb 25 18:27:00: MK5(0): New serial state = 0xA105 Feb 25 18:27:00: MK5(0): DCD is up. Feb 25 18:27:00: Serial0: HDLC myseq 18, mineseen 0*, yourseen 18, line down Feb 25 18:27:01: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to down Config on router 2: interface Serial0 ip address 1.1.1.2 255.255.255.0 clockrate 56000 ! interface Serial1 ip address 2.2.2.2 255.255.255.0 clockrate 56000 Log entries on Router 2: None SH IP INTERFACE BRIEF on Router 2: R2#sh ip int brief Interface IP-Address OK? Method Status Protocol Serial0 1.1.1.2 YES NVRAM up down Serial1 2.2.2.2 YES NVRAM up up R2#sh controller s 0 MK5 unit 0, NIM slot 0, NIM type code 7, NIM version 1 idb = 0x44A4, driver structure at 0xABDAB8, regaddr = 0x8000300 IB at 0x6006E64: mode=0x0108, local_addr=0, remote_addr=0 N1=1524, N2=1, scaler=100, T1=1000, T3=2000, TP=1 buffer size 1524 DCE V.35 serial cable attached, clockrate 56000 DEBUG SERIAL INTERFACE on Router 2: Feb 25 18:30:25: Serial0: HDLC myseq 38, mineseen 0, yourseen 0, line down .Feb 25 18:30:26: Serial0: attempting to restart .Feb 25 18:30:26: MK5(0): Deasserting DSR .Feb 25 18:30:26: MK5(0): Deasserting DSR .Feb 25 18:30:26: MK5(0): Reset .Feb 25 18:30:26: MK5(0): Asserting DSR .Feb 25 18:30:26: MK5(0): Deasserting LTST .Feb 25 18:30:26: MK5(0): Asserting DCD .Feb 25 18:30:26: MK5(0): New serial state = 0x6017 .Feb 25 18:30:26: MK5(0): DTR is up. .Feb 25 18:30:30: MK5(0): New serial state = 0x603E .Feb 25 18:30:30: MK5(0): DTR is down. .Feb 25 18:30:30: MK5(0): New serial state = 0x6016 .Feb 25 18:30:30: MK5(0): DTR is up. .Feb 25 18:30:35: MK5(0): New serial state = 0x6016 .Feb 25 18:30:35: MK5(0): DTR is up. .Feb 25 18:30:35: Serial0: HDLC myseq 39, mineseen 0, yourseen 0, line down .Feb 25 18:30:45: MK5(0): New serial state = 0x6016 .Feb 25 18:30:45: MK5(0): DTR is up. .Feb 25 18:30:45: Serial0: HDLC myseq 40, mineseen 0, yourseen 0, line down .Feb 25 18:30:50: MK5(0): New serial state = 0x6036 .Feb 25 18:30:50: MK5(0): DTR is down. .Feb 25 18:30:50: MK5(0): New serial state = 0x6016 .Feb 25 18:30:50: MK5(0): DTR is up. .Feb 25 18:30:55: MK5(0): New serial state = 0x6016 .Feb 25 18:30:55: MK5(0): DTR is up. .Feb 25 18:30:55: Serial0: HDLC myseq 41, mineseen 0, yourseen 0, line down .Feb 25 18:30:56: Serial0: attempting to restart .Feb 25 18:30:56: MK5(0): Deasserting DSR .Feb 25 18:30:56: MK5(0): Deasserting DSR .Feb 25 18:30:56: MK5(0): Reset .Feb 25 18:30:56: MK5(0): Asserting DSR .Feb 25 18:30:56: MK5(0): Deasserting LTST .Feb 25 18:30:56: MK5(0): Asserting DCD .Feb 25 18:30:56: MK5(0): New serial state = 0x6017 .Feb 25 18:30:56: MK5(0): DTR is up. .Feb 25 18:31:00: MK5(0): New serial state = 0x603E .Feb 25 18:31:00: MK5(0): DTR is down. .Feb 25 18:31:00: MK5(0): New serial state = 0x6016 .Feb 25 18:31:00: MK5(0): DTR is up. .Feb 25 18:31:05: MK5(0): New serial state = 0x6016 .Feb 25 18:31:05: MK5(0): DTR is up. .Feb 25 18:31:05: Serial0: HDLC myseq 42, mineseen 0, yourseen 0, line down R2# Thanks, Andy Fernandes Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=36423&t=36423 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]