Hello,
The title says it all: Arris C3 TM502G Stuck in MTA DHCP DISCOVER/DHCP OFFER loop. The cable modem part and the CPE behind the modem work just fine, but the MTA will not accept the offer from the DHCP server. We've followed the posts on this site to the letter and I've set up many many sites with Arris CMTS 1500s so I'm pretty sure the problem is in the C3 config. In the advanced features of the EMTA under " MTA DHCP PARAMETERS " I see that the "MTA FQDN" is incorrect. It's getting the FQDN of the cable modem. Any ideas?
Thanks,
Eric
I am sure you don't want to hear it, but what you are describing is classic behavior for an Arris modem receiving an invalid DHCP Offer. There really is not much on a CMTS that will affect whether a device will accecpt a DHCP Offer, but here it is so you can make the determination.
1. The subnet the MTA is getting the offer for is not able to communicate with the DHCP server. Why, DHCP Discover/Offers are broadcast DHCP Request/Acks are unicast, this could be caused by access lists, route problems etc...
Thats about it everything else has to do with the DHCP server.
Fortunately, you are using an Arris modem it makes this pretty easy to troubleshoot, for the record this is the same thing that Arris will tell you if you call their support.
First you need to be able to communicate with the modem via telnet/ssh, if you are not using the telnet image it is no problem you can turn on telnet temporarily via the web interface. Navigate to http://[Cable Modem IP]/techsupport.htm where you can turn on telnet/ssh on a temporary basis. (you need the password of the day to make changes)
Then telnet to the device using the Password of the day for the password
here is the next week worth of Passwords of the day if your using the default Seed
Date : Password of the Day
-----------------------------
03/10/10: 3UI2YWBZWV
03/11/10: 9463VC3Z9Z
03/12/10: 64Y3MG9LAY
03/13/10: KZJ604S3IJ
03/14/10: O7J6JZRJCK
03/15/10: S7V6USQKFL
03/16/10: IZTIO7UMFU
03/17/10: W39IPCRMFT
you can then navigate like so
mta (then press enter)
mtaDhcpACK (then press enter)
despite its name mtaDhcpACK actually shows the Offer/Request and Ack, your offer should look something like this
Message type (op) /BOOTREQUEST=1, BOOTREPLY=2/:= 2
Hardware address type (htype) = 1
Hardware address length (hlen) = 6
Message hops (hops) = 1
Transaction ID (xid) = 0x6574fb4
Seconds elapsed since addr acq or renewal (secs) = 0
Flags (flags) = 0x0
MTA client IP Address (ciaddr) = 0.0.0.0
MTA client IP Address (yiaddr) = 10.1.81.227
Next server IP (siaddr) = 192.168.224.40
Relay agent IP (giaddr) = 10.1.0.1
Client HW Address (chaddr) = 00:15:a3:f1:28:78
Server host name (sname) =
Boot file name (file) = mta.bin
Optional Parameters field (options) =
Option 53 (TLV): 35 01 02 (DHCP_OFFER)
Option 54 (TLV): 36 04 42dae00e
Option 51 (TLV): 33 04 00093a80
Option 12 (TLV): 0c 0f 6d7461303030666230386338376434
Option 15 (TLV): 0f 0f 6d74612e6361626c656d6f2e6e6574
Option 01 (TLV): 01 04 ffffe000
Option 03 (TLV): 03 04 0a014001
Option 02 (TLV): 02 04 ffffb9b0
Option 06 (TLV): 06 08 42dae00e42daf50d
Option 07 (TLV): 07 04 42dae00e
Option 122 (TLV): 7a 1f
Option 122 SubOption 03 (TLV): 03 12 00036d7461076361626c656d6f036e657400
Option 122 SubOption 06 (TLV): 06 09 054241534943013100
Option 00 (TLV): 00 00
Option 00 (TLV): 00 00
Option 00 (TLV): 00 00
Option 00 (TLV): 00 00
Option 00 (TLV): 00 00
Option 00 (TLV): 00 00
Option 00 (TLV): 00 00
Option 00 (TLV): 00 00
Its hex encoded so you would have to decode it if you wanted to see what the individual options said but, what you are looking for is to make sure is:
1. you have all the relevant options, this should be 1,2,3,6,7,12,15,51,53,54,122.3,122.6
2. you have a bootfile-name, and a next server NOTE: depends on your provisioning method, some methods don't require a bootfile name, i.e. gupi-mac
3. you have a valid hostname and domain name and that they make a valid, but not necessarily resolvable FQDN. you can check wikipedia/IEEE for the definition of a valid hostname and/or domain name if there is any question NOTE: the underscore character is not allowed in a hostname but the hyphen character is.
you can decode the hostname like so using http://www.asciitable.com/
Option 12 (TLV): 0c 0f 6d7461303030666230386338376434
0c = option 12
0f = length 15
hex Dec Ascii
6d = 109 = m
74 = 116 = t
61 = 97 = a
30 = 48 = 0
30 = 48 = 0
30 = 48 = 0
66 = 102 = f
62 = 98 = b
30 = 48 = 0
38 = 56 = 8
63 = 99 = c
38 = 56 = 8
37 = 55 = 7
64 = 100 = d
34 = 52 = 4
this one decodes to mta000fb08c87d4 which is a valid hostname
if you execute the command
resetMTA (then press enter) while your in a telnet session you should see the MTA come up and it will spit out the errors if any, I seem to recall having to enable certain debugging features to enable this but can't recall how to do so so your mileage may vary. When I did it on a working MTA I did not get any messages but there is not a problem, so that is expected, when I did have a problem it was spitting out the dhcp option that was missing.
Thanks,
Jason
Jason,
I tried all that. Check this out:
[ 6] MTA> disFQDN
disFQDN
Mta Device FQDN = TM502G0015A2461589.mta.domain.net
That FQDN is theFQDN of the Cable Modem side in the dhcpd.conf Not the MTA:
# TM502G0015A2461589 - 10.242.0.69
host TM502G0015A2461589 {
option tftp-server-name "65.255.236.3";
option bootfile-name "BcnBusinessSWTESTME.cm";
hardware ethernet 00:15:a2:46:15:89;
fixed-address 10.242.0.69;
}
# MTA0015a246158a - 10.242.0.75
host MTA0015a246158a {
hardware ethernet 00:15:a2:46:15:8a;
fixed-address 10.242.0.75;
}
Is that weird or what? Could that be the problem?
Thanks,
Eric
where is option hostname set in dhcpd.conf? i.e. global scope, subnet, shared-network, host etc...
On the DHCP offer, on the mta I am testing with, the hostname is showing the mac of the CPE behind the cable modem, however on the DHCP ack it is showing the right one, I think it is a bug not sure if it is on the modem, dhcpd or the cmts, but it should not be a life threatening one.
I don't think that will cause a problem, unless the modem has the same fqdn.
What provstate are you in, a working modem should be in 1(pass)?
What about provmethod?
Can you post your dhcpOffer/Ack?
Thanks,
Jason
Jason,
It's set in the global scope. We use gupi MAC MTA. I primarily use CMTS 1500s and have never had this issue. This leads me to believe it's a C3 issue.
Thanks,
Eric
post your offer and I can help you troubleshoot the problem
I have two pcap files. Will that help? Or I have this from the telnet session of the device:
MTA Dhcp OFFER
~~~~~~~~~~~~~~~~
Message type (op) /BOOTREQUEST=1, BOOTREPLY=2/:= 0
Hardware address type (htype) = 0
Hardware address length (hlen) = 0
Message hops (hops) = 0
Transaction ID (xid) = 0x0
Seconds elapsed since addr acq or renewal (secs) = 0
Flags (flags) = 0x0
MTA client IP Address (ciaddr) = 0.0.0.0
MTA client IP Address (yiaddr) = 0.0.0.0
Next server IP (siaddr) = 0.0.0.0
Relay agent IP (giaddr) = 0.0.0.0
Client HW Address (chaddr) = 00:00:00:00:00:00
Server host name (sname) =
Boot file name (file) =
Optional Parameters field (options) =
Option 00 (TLV): 00 00
MTA Dhcp REQUEST
~~~~~~~~~~~~~~~~
Message type (op) /BOOTREQUEST=1, BOOTREPLY=2/:= 0
Hardware address type (htype) = 0
Hardware address length (hlen) = 0
Message hops (hops) = 0
Transaction ID (xid) = 0x0
Seconds elapsed since addr acq or renewal (secs) = 0
Flags (flags) = 0x0
MTA client IP Address (ciaddr) = 0.0.0.0
MTA client IP Address (yiaddr) = 0.0.0.0
Next server IP (siaddr) = 0.0.0.0
Relay agent IP (giaddr) = 0.0.0.0
Client HW Address (chaddr) = 00:00:00:00:00:00
Server host name (sname) =
Boot file name (file) =
Optional Parameters field (options) =
Option 00 (TLV): 00 00
MTA Dhcp ACK
~~~~~~~~~~~~~~~~
Message type (op) /BOOTREQUEST=1, BOOTREPLY=2/:= 0
Hardware address type (htype) = 0
Hardware address length (hlen) = 0
Message hops (hops) = 0
Transaction ID (xid) = 0x0
Seconds elapsed since addr acq or renewal (secs) = 0
Flags (flags) = 0x0
MTA client IP Address (ciaddr) = 0.0.0.0
MTA client IP Address (yiaddr) = 0.0.0.0
Next server IP (siaddr) = 0.0.0.0
Relay agent IP (giaddr) = 0.0.0.0
Client HW Address (chaddr) = 00:00:00:00:00:00
Server host name (sname) =
Boot file name (file) =
Optional Parameters field (options) =
Option 00 (TLV): 00 00
CM Dhcp OFFER
~~~~~~~~~~~~~~~~
Message type (op) /BOOTREQUEST=1, BOOTREPLY=2/:= 2
Hardware address type (htype) = 1
Hardware address length (hlen) = 6
Message hops (hops) = 0
Transaction ID (xid) = 0x4640637
Seconds elapsed since addr acq or renewal (secs) = 0
Flags (flags) = 0x0
CM client IP Address (ciaddr) = 0.0.0.0
CM client IP Address (yiaddr) = 10.242.0.69
Next server IP (siaddr) = 65.255.236.3
Relay agent IP (giaddr) = 0.0.0.0
Client HW Address (chaddr) = 00:15:a2:46:15:89
Server host name (sname) =
Boot file name (file) =
Optional Parameters field (options) =
Option 53 (TLV): 35 01 02 (DHCP_OFFER)
Option 54 (TLV): 36 04 8b8e9a76
Option 51 (TLV): 33 04 0000a8c0
Option 66 (TLV): 42 0c 36352e3235352e3233362e33
Option 67 (TLV): 43 16 42636e427573696e6573735357544553544d452e636d
Option 01 (TLV): 01 04 fffff000
Option 03 (TLV): 03 04 0af20001
Option 02 (TLV): 02 04 ffff9d90
Option 04 (TLV): 04 04 41ffec03
Option 07 (TLV): 07 04 41ffec03
Option 06 (TLV): 06 08 d8122903d81229b7
Option 12 (TLV): 0c 12 544d35303247303031354132343631353839
Option 15 (TLV): 0f 0e 6d74612e646f6d61696e2e6e6574
Option 122 (TLV): 7a 24
Option 122 SubOption 01 (TLV): 01 04 0af20001
Option 122 SubOption 03 (TLV): 03 11 00036d746106646f6d61696e036e657400
Option 122 SubOption 06 (TLV): 06 09 054241534943013100
CM Dhcp REQUEST
~~~~~~~~~~~~~~~~
Message type (op) /BOOTREQUEST=1, BOOTREPLY=2/:= 1
Hardware address type (htype) = 1
Hardware address length (hlen) = 6
Message hops (hops) = 0
Transaction ID (xid) = 0x4640637
Seconds elapsed since addr acq or renewal (secs) = 0
Flags (flags) = 0x0
CM client IP Address (ciaddr) = 0.0.0.0
CM client IP Address (yiaddr) = 0.0.0.0
Next server IP (siaddr) = 0.0.0.0
Relay agent IP (giaddr) = 0.0.0.0
Client HW Address (chaddr) = 00:15:a2:46:15:89
Server host name (sname) =
Boot file name (file) =
Optional Parameters field (options) =
Option 53 (TLV): 35 01 03 (DHCP_REQUEST)
Option 57 (TLV): 39 02 03d8
Option 54 (TLV): 36 04 8b8e9a76
Option 50 (TLV): 32 04 0af20045
Option 51 (TLV): 33 04 0000a8c0
Option 60 (TLV): 3c 78 646f63736973322e303a3035333530313031303130323031303230333031303130343031303130353031303130363031303130373031306630383031313030393031303030613031303130623031313830633031303130643032303037303065303230303130306630313031313030343030303030303034
Option 55 (TLV): 37 0c 42430103020407060c0f7ab1
Option 61 (TLV): 3d 07 010015a2461589
Option 43 (TLV): 2b 63 020345434d030845434d3a454d544105023032060b362e312e3737542e534950070530352e303108063030303043410906544d353032470a19417272697320496e7465726163746976652c204c2e4c2e432e040f36434c424d55353953323238363230
CM Dhcp ACK
~~~~~~~~~~~~~~~~
Message type (op) /BOOTREQUEST=1, BOOTREPLY=2/:= 2
Hardware address type (htype) = 1
Hardware address length (hlen) = 6
Message hops (hops) = 0
Transaction ID (xid) = 0x4640637
Seconds elapsed since addr acq or renewal (secs) = 0
Flags (flags) = 0x0
CM client IP Address (ciaddr) = 0.0.0.0
CM client IP Address (yiaddr) = 10.242.0.69
Next server IP (siaddr) = 65.255.236.3
Relay agent IP (giaddr) = 0.0.0.0
Client HW Address (chaddr) = 00:15:a2:46:15:89
Server host name (sname) =
Boot file name (file) =
Optional Parameters field (options) =
Option 53 (TLV): 35 01 05 (DHCP_ACK)
Option 54 (TLV): 36 04 8b8e9a76
Option 51 (TLV): 33 04 0000a8c0
Option 66 (TLV): 42 0c 36352e3235352e3233362e33
Option 67 (TLV): 43 16 42636e427573696e6573735357544553544d452e636d
Option 01 (TLV): 01 04 fffff000
Option 03 (TLV): 03 04 0af20001
Option 02 (TLV): 02 04 ffff9d90
Option 04 (TLV): 04 04 41ffec03
Option 07 (TLV): 07 04 41ffec03
Option 06 (TLV): 06 08 d8122903d81229b7
Option 12 (TLV): 0c 12 544d35303247303031354132343631353839
Option 15 (TLV): 0f 0e 6d74612e646f6d61696e2e6e6574
Option 122 (TLV): 7a 24
Option 122 SubOption 01 (TLV): 01 04 0af20001
Option 122 SubOption 03 (TLV): 03 11 00036d746106646f6d61696e036e657400
Option 122 SubOption 06 (TLV): 06 09 054241534943013100
Thanks,
Eric
That log is showing that the MTA is NOT hearing the DHCP OFFER, which suggests a routing problem between the DHCP server and the Subnet you are trying to have the MTA come up on.
things to look for:
access-lists not allowing traffic through
bad route or gateway information
firwalls
Can you traceroute to the MTA gateway from the dhcp server?
did you try the resetMTA command while connected to the telnet interface? does it show any extra information?
kwesibrunee,
Does this web access work for all TM502g code releases?
I have apparent MTA DHCP issues as well and would like to see the modems perspective on what's wrong. However I get the message "Access to this web page is currently unavailable" when I try.
I'm running the following realease and only have this one MTA.
sysDescr:ARRIS DOCSIS 2.0 / PacketCable 1.0 Touchstone Telephony Modem <
HW_REV: 02; VENDOR: Arris Interactive, L.L.C.; BOOTR: 6.03; SW_REV: 5.0.50D.D11PLUS; MODEL: TM502G>>
Eric send me a line at velgroup@aol.com , i need to talk to you regarding a project.
kwesibrunee,
Does this web access work for all TM502g code releases?
I have apparent MTA DHCP issues as well and would like to see the modems perspective on what's wrong. However I get the message "Access to this web page is currently unavailable" when I try.
I'm running the following realease and only have this one MTA.
sysDescr:ARRIS DOCSIS 2.0 / PacketCable 1.0 Touchstone Telephony Modem <>