Hello, I'm new in this forum.
Last week I noticed a small problem in my network. Cable modems and host have a strange problem in renewing IP addressess.
When modem boots up it gets IP and config from tftp server and looks fine and works.
After half of dhcp-lease time ( like in dhcp std. ) modem and CPE tries to renew its address.
In this case I can see in logs many entries like this:
Mar 13 06:25:14 172.16.1.210 CABLEMODEM[DOCSIS]: <68010100>DHCP RENEW sent - No response
and log from dhcp server looks like :
Mar 14 06:56:27 GW-INTERSAT dhcpd: DHCPREQUEST for 172.16.1.210 from 00:15:96:78:a6:ee via eth0
Mar 14 06:56:27 GW-INTERSAT dhcpd: DHCPACK on 172.16.1.210 to 00:15:96:78:a6:ee via eth0
Mar 14 06:56:59 GW-INTERSAT dhcpd: DHCPREQUEST for 172.16.1.210 from 00:15:96:78:a6:ee via eth0
Mar 14 06:56:59 GW-INTERSAT dhcpd: DHCPACK on 172.16.1.210 to 00:15:96:78:a6:ee via eth0
Mar 14 06:58:03 GW-INTERSAT dhcpd: DHCPREQUEST for 172.16.1.210 from 00:15:96:78:a6:ee via eth0
Mar 14 06:58:03 GW-INTERSAT dhcpd: DHCPACK on 172.16.1.210 to 00:15:96:78:a6:ee via eth0
Mar 14 06:58:06 GW-INTERSAT dhcpd: DHCPREQUEST for 172.16.1.210 from 00:15:96:78:a6:ee via eth0
Mar 14 06:58:06 GW-INTERSAT dhcpd: DHCPACK on 172.16.1.210 to 00:15:96:78:a6:ee via eth0
Mar 14 06:58:14 GW-INTERSAT dhcpd: DHCPREQUEST for 172.16.1.210 from 00:15:96:78:a6:ee via eth0
Mar 14 06:58:14 GW-INTERSAT dhcpd: DHCPACK on 172.16.1.210 to 00:15:96:78:a6:ee via eth0
Mar 14 06:58:29 GW-INTERSAT dhcpd: DHCPREQUEST for 172.16.1.210 from 00:15:96:78:a6:ee via eth0
Mar 14 06:58:29 GW-INTERSAT dhcpd: DHCPACK on 172.16.1.210 to 00:15:96:78:a6:ee via eth0
Mar 14 06:59:00 GW-INTERSAT dhcpd: DHCPREQUEST for 172.16.1.210 from 00:15:96:78:a6:ee via eth0
Mar 14 06:59:00 GW-INTERSAT dhcpd: DHCPACK on 172.16.1.210 to 00:15:96:78:a6:ee via eth0
Mar 14 07:00:03 GW-INTERSAT dhcpd: DHCPREQUEST for 172.16.1.210 from 00:15:96:78:a6:ee via eth0
Mar 14 07:00:03 GW-INTERSAT dhcpd: DHCPACK on 172.16.1.210 to 00:15:96:78:a6:ee via eth0
Modems and CPE reply to ping request and works ok but logs are growing very fast.
Have you any suggestions how to diagnose this issue ?
The log file you posted is from the same mac address, thinking it's a modem or mta that doesn't like the file and keeps trying. check that state of that modem on the cmts and you will find your answer
Log state from c3 :
DS/US Prim Online Timing Rec CPE IP address MAC address DOC
Interface SID state offset power
C1/0/U1.0 126 online(pt) 433 -4.2 2/5 172.16.1.14 0013.1155.07ae D2.0A
Example logs from dhcp.log :
Mar 17 17:02:54 GW-INTERSAT dhcpd: DHCPREQUEST for 172.16.1.14 from 00:13:11:55:07:ae via eth0
Mar 17 17:02:54 GW-INTERSAT dhcpd: DHCPACK on 172.16.1.14 to 00:13:11:55:07:ae via eth0
Mar 17 17:03:02 GW-INTERSAT dhcpd: DHCPREQUEST for 172.16.1.14 from 00:13:11:55:07:ae via eth0
Mar 17 17:03:02 GW-INTERSAT dhcpd: DHCPACK on 172.16.1.14 to 00:13:11:55:07:ae via eth0
Example log from syslog :
Mar 17 17:02:51 172.16.1.14 CABLEMODEM[DOCSIS]: <68010100>DHCP RENEW sent - No response
Mar 17 17:02:54 172.16.1.14 CABLEMODEM[DOCSIS]: <68010100>DHCP RENEW sent - No response
Mar 17 17:03:02 172.16.1.14 CABLEMODEM[DOCSIS]: <68010100>DHCP RENEW sent - No response
Mar 17 17:03:16 172.16.1.14 CABLEMODEM[DOCSIS]: <68010100>DHCP RENEW sent - No response
Mar 17 17:03:48 172.16.1.14 CABLEMODEM[DOCSIS]: <68010100>DHCP RENEW sent - No response
I can normally ping CM :
PING 172.16.1.14 (172.16.1.14) 56(84) bytes of data.
64 bytes from 172.16.1.14: icmp_seq=1 ttl=64 time=5.93 ms
64 bytes from 172.16.1.14: icmp_seq=2 ttl=64 time=13.1 ms
Problem is that log files grow very fast.