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Rouge DHCP server on my network

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emkowale
Rouge DHCP server on my network

Hello,

This might sound like a dumb question, but is there a way I can disable other DHCP requests on the cable network? I use the Arris CMTS 1000's and CMTS 1500's. I had a subscriber that plugged our cable modem into one of the LAN ports on his router and it back fed IPs to other cable modems in the network. This seems like it should be a simple fix that I'll missing.

Thanks in advance,
emkowale

hinzoo
Use the bootp config from

Use the bootp config from admin menu and set bootp-relay to relay-tagging-enabled. Also You have to set dhcp server address in bootp-list

cmcaldas
Block it at the modem

One of the cons when you run a bridge cmts... but I would recommend you block at the modem side. here's a sample modem file you can test before sending it to all the modems ;-)

FileVersion = Version 6.0
03 (Net Access Control) = 1

04 (Class of Service Encodings Block)
S01 Class ID = 1
S02 Maximum DS Rate = 384000
S03 Maximum US Rate = 128000
S04 US Channel Priority = 7
S06 Maximum US Xmit Burst = 3044
11 (SNMP LLC FILTER) = 1.3.6.1.2.1.69.1.6.2.1.2.1 %integer = 1
11 (SNMP LLC FILTER) = 1.3.6.1.2.1.69.1.6.2.1.3.1 %integer = 0
11 (SNMP LLC FILTER) = 1.3.6.1.2.1.69.1.6.2.1.4.1 %integer = 1
11 (SNMP LLC FILTER) = 1.3.6.1.2.1.69.1.6.2.1.5.1 %integer = 2048
11 (SNMP LLC FILTER) = 1.3.6.1.2.1.69.1.6.2.1.2.2 %integer = 1
11 (SNMP LLC FILTER) = 1.3.6.1.2.1.69.1.6.2.1.3.2 %integer = 0
11 (SNMP LLC FILTER) = 1.3.6.1.2.1.69.1.6.2.1.4.2 %integer = 1
11 (SNMP LLC FILTER) = 1.3.6.1.2.1.69.1.6.2.1.5.2 %integer = 2054
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.2.1 %integer = 1
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.3.1 %integer = 1
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.4.1 %integer = 1
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.5.1 %integer = 2
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.6.1 %integer = 2
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.7.1 %ipaddr = 0.0.0.0
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.8.1 %ipaddr = 0.0.0.0
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.9.1 %ipaddr = 10.0.0.0
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.10.1 %ipaddr = 255.0.0.0
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.2.2 %integer = 1
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.3.2 %integer = 1
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.4.2 %integer = 1
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.5.2 %integer = 3
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.6.2 %integer = 2
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.7.2 %ipaddr = 0.0.0.0
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.8.2 %ipaddr = 0.0.0.0
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.9.2 %ipaddr = 192.168.0.0
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.10.2 %ipaddr = 255.255.0.0
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.2.3 %integer = 1
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.3.3 %integer = 1
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.4.3 %integer = 1
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.5.3 %integer = 1
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.6.3 %integer = 2
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.7.3 %ipaddr = 0.0.0.0
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.8.3 %ipaddr = 0.0.0.0
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.9.3 %ipaddr = 172.16.0.0
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.10.3 %ipaddr = 255.240.0.0
11 (SNMP MIB Object) = 1.3.6.1.2.1.69.1.6.3.0 %Integer = 2
11 (SNMP MIB Object) = 1.3.6.1.2.1.69.1.6.1.0 %Integer = 1
18 (Maximum Number of CPE) = 3

emkowale
Which program do you use for config files?

Hello,

Which program do you use for config files? I use docsis for Linux and I look at your above post and it seems a bit Greek to me. The format is unusual.

Thanks,
emkowale

cmcaldas
Program for config files

I use the Motorola Surfboard docsis editor, it allows you to view it as text as well. there's other programs out there, I've been trying to get a copy of packet ace, so if anybody wants to trade, let me know ;-)

emkowale
Is it free?

I use docsis because it's free. I have packet ace because one of my clients bought a bunch of arris modems from arris. I'm not sure if that's free or not.

emkowale

cmcaldas
would like to try it

I haven't used packet ace, but would like to try it. I only use the Motorola Surfboard docsis editor and wanted to see if there's much of a difference.
I can send you a copy from my younsedit account if you could email me the Packet ace.

Thanks

cmcaldas@gmail.com

laceytech
config file blocking of rogue dhcp server

I find that blocking the ports in the config file is more effective than blocking a range of IP addresses
This way any private address block that is used on a router plugged in backwards will be blocked
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.2.67 %integer = 4
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.3.67 %integer = 1
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.4.67 %integer = 2
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.5.67 %integer = 1
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.6.67 %integer = 2
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.7.67 %ipaddr = 0.0.0.0
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.8.67 %ipaddr = 0.0.0.0
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.9.67 %ipaddr = 0.0.0.0
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.10.67 %ipaddr = 0.0.0.0
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.11.67 %integer = 17
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.12.67 %integer = 68
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.13.67 %integer = 68
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.14.67 %integer = 67
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.15.67 %integer = 67
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.2.68 %integer = 4
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.3.68 %integer = 1
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.4.68 %integer = 1
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.5.68 %integer = 1
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.6.68 %integer = 2
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.7.68 %ipaddr = 0.0.0.0
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.8.68 %ipaddr = 0.0.0.0
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.9.68 %ipaddr = 0.0.0.0
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.10.68 %ipaddr = 0.0.0.0
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.11.68 %integer = 17
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.12.68 %integer = 67
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.13.68 %integer = 67
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.14.68 %integer = 68
11 (SNMP IP FILTER) = 1.3.6.1.2.1.69.1.6.4.1.15.68 %integer = 68

I hope this helps
Jim
Laceytech LLC
www.laceytech.com

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