option 122 revisited

Hi all,

I need help with option 122. I've been browsing forums for days before I run into this obstacle. It is very hard for me to figure out what is a problem for my MTAs.

Hardware I use is BSR1000, modems are SBV5121, server is fedora, dhcp is isc-dhcpd-4.0.0.

I have gradually worked my way through dhcpd.conf - I managed to boot up CM, assign it fixed IP address, and send it option 122 so it wakes MTA up. Problem is that MTA keeps sending dhcp discover but it seems not to "hear" my dhcp offers from the server.

here goes some of the debug info from the CMTS:

[09/11-15:02:13.99:Udp-dhcp]-D-Relay BOOTREQ DISCOVER packet to server with src 10.14.0.1, dst 10.200.200.5, srcport 68, dstport 67 ciaddr 0.0.0.0, yiaddr 0.0.0.0, giaddr 10.14.0.1, chaddr 00:1a:ad:a9:20:f0, xid 0x00618d93
[09/11-15:02:13.97:Udp]-D-Udp packet recvd with src 10.200.200.5, dst 10.14.0.1, srcport 67, dstport 67
[09/11-15:02:13.97:Udp-dhcp]-D-Relay BOOTREP OFFER to client with src 10.123.128.1, dst 255.255.255.255, srcport 67, dstport 68 ciaddr 0.0.0.0, yiaddr 10.123.128.11, giaddr 10.123.128.1, chaddr 00:1a:ad:a9:20:f0, xid 0x00618d93
[09/11-15:02:21.99:Udp]-D-Udp packet recvd with src 0.0.0.0, dst 255.255.255.255, srcport 68, dstport 67
[09/11-15:02:21.97:Udp-dhcp]-D-Relay BOOTREQ DISCOVER packet to server with src 10.14.0.1, dst 10.200.200.5, srcport 68, dstport 67 ciaddr 0.0.0.0, yiaddr 0.0.0.0, giaddr 10.14.0.1, chaddr 00:1a:ad:a9:20:f0, xid 0x00618d93
[09/11-15:02:21.97:Udp]-D-Udp packet recvd with src 10.200.200.5, dst 10.14.0.1, srcport 67, dstport 67
[09/11-15:02:21.97:Udp-dhcp]-D-Relay BOOTREP OFFER to client with src 10.123.128.1, dst 255.255.255.255, srcport 67, dstport 68 ciaddr 0.0.0.0, yiaddr 10.123.128.11, giaddr 10.123.128.1, chaddr 00:1a:ad:a9:20:f0, xid 0x00618d93


here is tail of the boot log:

[root@XXX ~]# tail /var/log/boot.log
Sep 11 14:26:56 XXX dhcpd: DHCPREQUEST for 10.100.101.254 (10.200.200.5) from 00:11:2f:b4:1b:6f (XXX-catv) via 10.14.0.1
Sep 11 14:26:56 XXX dhcpd: DHCPACK on 10.100.101.254 to 00:11:2f:b4:1b:6f (XXX-catv) via 10.14.0.1
Sep 11 14:27:00 XXX dhcpd: DHCPDISCOVER from 00:1a:ad:a9:20:f0 via 10.14.0.1
Sep 11 14:27:00 XXX dhcpd: DHCPOFFER on 10.123.128.11 to 00:1a:ad:a9:20:f0 via 10.14.0.1
Sep 11 14:27:08 XXX dhcpd: DHCPDISCOVER from 00:1a:ad:a9:20:f0 via 10.14.0.1
Sep 11 14:27:08 XXX dhcpd: DHCPOFFER on 10.123.128.11 to 00:1a:ad:a9:20:f0 via 10.14.0.1


here is a piece of tcpdump sniff:

14:29:11.997584 IP (tos 0x0, ttl 255, id 14443, offset 0, flags [none], proto UDP (17), length 592) 10.14.0.1.bootpc > 10.200.200.5.bootps: BOOTP/DHCP, Request from 00:1a:ad:a9:20:f0 (oui Unknown), length 564, hops 1, xid 0x1c10f47, Flags [Broadcast]
Gateway-IP 10.14.0.1
Client-Ethernet-Address 00:1a:ad:a9:20:f0 (oui Unknown)
Vendor-rfc1048 Extensions
Magic Cookie 0x63825363
DHCP-Message Option 53, length 1: Discover
MSZ Option 57, length 2: 548
Vendor-Option Option 43, length 123: 2.4.69.77.84.65.4.24.49.53.56.49.54.49.55.51.48.51.51.51.48.57.54.50.48.49.48.49.50.48.48.52.5.3.49.46.48.6.28.83.66.86.53.49.50.49.69.45.50.46.49.55.46.49.46.50.45.83.67.77.49.48.45.83.72.80.67.7.3.56.46.53.8.3.0.26.173.9.8.83.66.86.53.49.50.49.69.10.20.77.111.116.111.114.111.108.97.32.67.111.114.112.111.114.97.116.105.111.110.31.6.0.26.173.169.32.240.32.4.0.0.94.49
Vendor-Class Option 60, length 72: "pktc1.0:051E0101000201020901010A01010B060103050608090D010110010912020007"
Parameter-Request Option 55, length 8:
Hostname, Domain-Name, Subnet-Mask, Default-Gateway
Time-Zone, Domain-Name-Server, LOG, Option 122
Client-ID Option 61, length 7: ether 00:1a:ad:a9:20:f0
Agent-Information Option 82, length 14:
Unknown SubOption 2, length 6:
0x0000: 001a ada9 20ee
Unknown SubOption 43, length 4:
0x0000: 0a0e 000b
14:29:11.998171 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto UDP (17), length 377) 10.200.200.5.bootps > 10.14.0.1.bootps: BOOTP/DHCP, Reply,length 349, hops 1, xid 0x1c10f47, Flags [Broadcast]
Your-IP 10.123.128.11
Gateway-IP 10.14.0.1
Client-Ethernet-Address 00:1a:ad:a9:20:f0 (oui Unknown)
file "mta.bin"
Vendor-rfc1048 Extensions
Magic Cookie 0x63825363
DHCP-Message Option 53, length 1: Offer
Server-ID Option 54, length 4: 10.200.200.5
Lease-Time Option 51, length 4: 604800
Hostname Option 12, length 13: "mta.XXX.xx"
Domain-Name Option 15, length 9: "XXX.xx"
Subnet-Mask Option 1, length 4: 255.255.128.0
Default-Gateway Option 3, length 4: 10.123.128.1
Time-Zone Option 2, length 4: 7200
Domain-Name-Server Option 6, length 4: 10.200.200.5
LOG Option 7, length 4: 10.200.200.5
T122 Option 122, length 19: 122.17.3.5.1.10.200.200.5.6.8.66.65.83.73.67.1.49.0
Agent-Information Option 82, length 14:
Unknown SubOption 2, length 6:
0x0000: 001a ada9 20ee
Unknown SubOption 43, length 4:
0x0000: 0a0e 000b


Here is my dhcpd.conf:

ddns-update-style none;
default-lease-time 600;
option domain-name "XXX.xx";
ddns-domainname "XXX.xx";
log-facility local7;
omapi-port 7911;

# option space docsis-mta;
# option docsis-mta.dhcp-server-1 code 1 = ip-address;
# option docsis-mta.dhcp-server-2 code 2 = ip-address;
# option docsis-mta.prov-server code 3 = string;
# option docsis-mta.kerberos code 6 = string;
#
# option docsis-mta-encap code 122 = encapsulate docsis-mta;

option voip122 code 122 = string;

class "cm" {
match if substring(option vendor-class-identifier,0,6) = "docsis";
spawn with option agent.remote-id;
default-lease-time 604800;
max-lease-time 604800;
min-lease-time 302400;

option tftp-server-name "10.200.200.5";
option time-servers 10.200.200.5;
option time-offset 7200;
option log-servers 10.200.200.5;
option domain-name "XXX.xx";

# vendor-option-space docsis-mta;
# option docsis-mta.dhcp-server-1 10.200.200.5;
# option docsis-mta.dhcp-server-2 10.200.200.6;
# option voip122 7a:01:04:0a:c8:c8:05;
option voip122 01:04:0a:c8:c8:05;
}

class "emta" {
match if substring(option vendor-class-identifier,0,8) = "pktc1.0:";
spawn with option agent.remote-id;
default-lease-time 604800;
max-lease-time 604800;
min-lease-time 302400;
option tftp-server-name "10.200.200.5";
option time-servers 10.200.200.5;
option time-offset 7200;
option log-servers 10.200.200.5;
option domain-name "XXX.xx";
# vendor-option-space docsis-mta-encap;
# option voip122 7a:17:01:04:0a:c8:c8:05:03:05:01:0a:c8:c8:05:06:08:42:41:53:49:43:01:31:00;
option voip122 7a:11:03:05:01:0a:c8:c8:05:06:08:42:41:53:49:43:01:31:00;
# option voip122 16:01:04:0a:c8:c8:05:03:05:01:0a:c8:c8:05:06:08:42:41:53:49:43:01:31:00;
}

class "cpe" {
}

shared-network CABLE {
option domain-name-servers 10.200.200.5;
default-lease-time 600;
max-lease-time 7200;
option time-servers 10.200.200.5;
option log-servers 10.200.200.5;
subnet 10.0.0.0 netmask 255.0.0.0 {

pool {
range 10.14.0.5 10.14.0.9;
option subnet-mask 255.254.0.0;
option routers 10.14.0.1;
next-server 10.200.200.5;
option tftp-server-name "10.200.200.5";
filename "normal.cfg";
allow members of "cm";

}

pool {
range 10.123.128.2 10.123.255.254;
option subnet-mask 255.255.128.0;
option routers 10.123.128.1;
next-server 10.200.200.5;
allow members of "emta";
ddns-updates on;
ddns-domainname "mta.XXX.xx";
option host-name "mta.yy";
}

pool {
range 10.100.100.2 10.100.101.254;
option routers 10.100.100.1;
option subnet-mask 255.255.254.0;
#allow members of "cpe";
}
} # end subnet of shared network
} # end shared-network CABLE

group pkt1 {
filename "PAKET-1.cfg";
option bootfile-name "PAKET-1.cfg";
option routers 10.11.0.1;
option subnet-mask 255.255.254.0;
}

group pkt2 {
filename "PAKET-2.cfg";
option bootfile-name "PAKET-2.cfg";
option routers 10.11.0.1;
option subnet-mask 255.255.254.0;
}

group disabled {
filename "disabled.cfg";
option bootfile-name "disabled.cfg";
option routers 10.11.0.1;
option subnet-mask 255.255.254.0;
}

group tester {
filename "normal.cfg";
option bootfile-name "normal.cfg";
option routers 10.14.0.1;
option subnet-mask 255.255.254.0;

#option docsis-mta.dhcp-server-1 10.200.200.5;
#vendor-option-space docsis-mta;

}

host test {
hardware ethernet 00:1a:ad:a9:20:ee;
fixed-address 10.14.0.11;
group "tester";
}

host test-mta {
hardware ethernet 00:1a:ad:a9:20:f0;
fixed-address 10.123.128.11;
option routers 10.123.128.1;
option subnet-mask 255.255.128.0;
option domain-name-servers 10.200.200.5;
option log-servers 10.200.200.5;
option tftp-server-name "10.200.200.5";
filename "mta.bin";
option bootfile-name "mta.bin";
option domain-name "XXX.xx";
ddns-domainname "mta.XXX.xx";
option host-name "mta.XXX.xx";
}

As you can tell from the above configuration, I've tried many different ways to send option 122 in a dhcp offer to MTA, whatever I did - it never got past dhcp discover - dhcp offer loop. Documentation for packet cable provisioning says that if no valid DHCP offer was made, MTA MUST perform another dhcp discover...I can surely ping both CM and CPE, so routing is unlikely to be the problem. I am sort of stuck - do not know what to debug anymore and my config is not working. I've tried using defined option space (vendor-option-space) but it never worked out for me, at the end I hand-encoded whole string according to the rfc3495. If I try sending string as RFC proposes it, it should NOT include "option code" at the start of the string, so real string should look, for example, if I wanted to send suboptions 3 and 6, like this option voip122 11:03:05:01:0a:c8:c8:05:06:08:42:41:53:49:43:01:31:00; however if I do not prepend it with hexed 122 than my tcpdump shows garbage instead of the de-hexed line. Therefore I used it in the form 7a:11:03:05:01:0a:c8:c8:05:06:08:42:41:53:49:43:01:31:00. I tried sending options 1,2,3, and 6, than I tried sending 1,3, and 6, than just 3 and 6 - nothing seems to help MTA accept dhcp offer.

Pretty please help me figure it out. I am not sure what to debug anymore - step where I am stuck has logical explanations, but it just seems like this will never work out for me. I cannot figure out what am I doing wrong. Thanks in advance.