I am using cisco 2811 router with 1 WIC-1T card for serial interface
Both router is connected by serial (DCE/DTE) interface and and ip is set as follows:
router 1: 192.168.1.1 255.255.255.0
router 1: 192.168.1.2 255.255.255.0
Problem: line protocol is showing down .
Example bellow :
R1#show ip interface brief Interface IP-Address OK? Method Status Protocol FastEthernet0/0 unassigned YES manual administratively down down FastEthernet0/1 unassigned YES manual administratively down down Serial0/3/0 192.168.1.1 YES manual up down Vlan1 unassigned YES manual administratively down down
Reason :
one of the reason is on DCE , clock rate is set to : no clock , as bellow example
R1#show controllers serial 0/3/0
Interface Serial0/3/0
Hardware is PowerQUICC MPC860
DCE V.35, no clock
idb at 0x81081AC4, driver data structure at 0x81084AC0
SCC Registers:
General [GSMR]=0x2:0x00000000, Protocol-specific [PSMR]=0x8
Events [SCCE]=0x0000, Mask [SCCM]=0x0000, Status [SCCS]=0x00
Transmit on Demand [TODR]=0x0, Data Sync [DSR]=0x7E7E
Interrupt Registers:
Config [CICR]=0x00367F80, Pending [CIPR]=0x0000C000
Mask [CIMR]=0x00200000, In-srv [CISR]=0x00000000
Command register [CR]=0x580
Port A [PADIR]=0x1030, [PAPAR]=0xFFFF
[PAODR]=0x0010, [PADAT]=0xCBFF
Port B [PBDIR]=0x09C0F, [PBPAR]=0x0800E
[PBODR]=0x00000, [PBDAT]=0x3FFFD
Port C [PCDIR]=0x00C, [PCPAR]=0x200
[PCSO]=0xC20, [PCDAT]=0xDF2, [PCINT]=0x00F
Receive Ring
rmd(68012830): status 9000 length 60C address 3B6DAC4
rmd(68012838): status B000 length 60C address 3B6D444
Transmit Ring
--More--Solve:
add clock rate by hand
R1#configure t R1#configure terminal Enter configuration commands, one per line. End with CNTL/Z. R1(config)#in R1(config)#interface se R1(config)#interface serial 0/3/0 R1(config-if)#clo R1(config-if)#clock r R1(config-if)#clock rate 1000000 R1(config-if)# %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/3/0, changed state to up