Configuring DHCP+TFTP for DOCSIS

Recently, it was necessary to configure the issuance of IP addresses to several old DOCSIS modems and the host located after the modem.
At hand was the Arris Cadant C3 and Thomson TCM-420 modems.

First of all, let’s start a DHCP server that will issue IP addresses to modems, for example, as I described in this article – Installing and configuring isc-dhcp-server.
And also we will launch a TFTP server on which there will be files for modems, for example, as I described in the article – Installing and Configuring a TFTP Server

Continue reading “Configuring DHCP+TFTP for DOCSIS”

Script backup configuration DOCSIS ARRIS Cadant C3 CMTS

Actually, this is my script:

# Backup DOCSIS CADANTS config
sleep 5
echo "user"
sleep 5
echo "password"
sleep 5
echo "enable"
sleep 2
echo "password"
sleep 2
echo "copy startup-configuration tftp://"
sleep 5
echo "exit"
) | telnet
mv /srv/tftp/cadant1.xml /backups/devices/docsis/`date +%Y-%m-%d`_cadant1.xml

Where – cadant, – tftp server.

You can add the script to /etc/crontab for automatic execution (for example, every day at one in the morning):

0 1 * * * root /path/to/script/ > /dev/null 2>&1

OID and MIB list for Arris Cadant C3

I’ll list a few oid below and briefly describe them.
Check the response to oid and mib in linux for example with the following command:

snmpwalk -v 2c -c public .

Connected modems (dcxUsStatsRegComplete) .

Upstream Indexes: .
Network Interface Status .
Description of network interfaces .
Network Interface Name .

SignalNoise upstream (docsIfSigQSignalNoise) .
SignalNoiseSNR upstream (docsIfSigQSignalNoiseSNR) .

Mibs for upstream power-level:

Number of modems on the upstream:

(dcxUsStatsOther) .
(dcxUsStatsRanging) .
(dcxUsStatsRngAborted) .
(dcxUsStatsRngComplete) .
(dcxUsStatsIpComplete) .
(dcxUsStatsAccessDenied) .

(UpstreamNum) .
(dcxUsStatsAvgUtil) .
(dcxUsStatsAvgContSlots) .
(docsIfSigQUnerroreds) .
(docsIfSigQCorrecteds) .
(docsIfSigQUncorrectables) .
(dcxUsStatsNumActiveUGS) .
(dcxUsStatsAvgUGSLastOneHour) .
(dcxUsStatsMaxUGSLastFiveMins) .

See also:
SNMP OID and MIB for interfaces