[Kea-users] Over-riding global settings in specific subnets / prefixes

mxhajduczenia at gmail.com mxhajduczenia at gmail.com
Fri May 3 20:16:12 UTC 2024


Good afternoon, 

 

I observed a rather surprising behavior today in Kea 2.4.1 DHCPv6 server. 

 

I have a global (shared) custom option value defined as follows. Note the
config file value 

 

      {

        "space": "vendor-4491",

        "name": "config-file",

        "code": 33,

        "data": "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg"

      },

 

In one of the subnets, I assigned a custom value as follows

 

                      {

                           "id": 102,

                           "interface": "enp6s18",               

                           "comment": "CMs connected to Vince's RPDs",

                           "subnet": "2600:6ce4:0:208::/64",

                           "relay": {

                                 "ip-addresses": [ "2600:6ce4:0:3e::1" ]

                           },

                           "pools": [

                                 {

                                      "pool": "2600:6ce4:0:208::2 -
2600:6ce4:0:208:ffff:ffff:ffff:ffff",

                                      "client-class": "ecm-vince",

                                      "option-data": [

                                            {

                                                 "space": "vendor-4491",

                                                 "name": "config-file",

                                                 "code": 33,

                                                 "data":
"WBDocCfg166_upgrade.cfg"

                                            },

                                            {

                                                 "space": "dhcp6",

                                                 "name": "dns-servers",

                                                 "code": 23,

                                                 "data":
"2600:6ce4:40:12c:8000::3"

                                            }

                                      ]

                                 }

                           ]

                      },

 

hoping that it would override the parameter value assigned globally.
Unfortunately, the TFTP server logs show that the previous config file value
is still being served. 

 

20:01:57.672602 IP6 2600:6ce4:0:208::24.59455 > 2600:6ce4:0:42::132.69:
TFTP, length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg"
octet blksize 1428 tsize 0

20:01:59.745978 IP6 2600:6ce4:0:208::27.44638 > 2600:6ce4:0:42::132.69:
TFTP, length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg"
octet blksize 1428 tsize 0

20:02:00.584499 IP6 2600:6ce4:0:208::39.36093 > 2600:6ce4:0:42::132.69:
TFTP, length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg"
octet blksize 1428 tsize 0

20:02:00.684559 IP6 2600:6ce4:0:208::2a.57747 > 2600:6ce4:0:42::132.69:
TFTP, length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg"
octet blksize 1428 tsize 0

20:02:03.390078 IP6 2600:6ce4:0:208::9.35267 > 2600:6ce4:0:42::132.69: TFTP,
length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg" octet
blksize 1428 tsize 0

20:02:04.210522 IP6 2600:6ce4:0:208::3b.39781 > 2600:6ce4:0:42::132.69:
TFTP, length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg"
octet blksize 1428 tsize 0

20:02:04.429295 IP6 2600:6ce4:0:208::6.39985 > 2600:6ce4:0:42::132.69: TFTP,
length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg" octet
blksize 1428 tsize 0

20:02:04.483974 IP6 2600:6ce4:0:208::38.41514 > 2600:6ce4:0:42::132.69:
TFTP, length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg"
octet blksize 1428 tsize 0

20:02:04.813712 IP6 2600:6ce4:0:208::3a.36185 > 2600:6ce4:0:42::132.69:
TFTP, length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg"
octet blksize 1428 tsize 0

20:02:05.034628 IP6 2600:6ce4:0:208::37.42895 > 2600:6ce4:0:42::132.69:
TFTP, length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg"
octet blksize 1428 tsize 0

20:02:05.035990 IP6 2600:6ce4:0:208::3.57665 > 2600:6ce4:0:42::132.69: TFTP,
length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg" octet
blksize 1428 tsize 0

20:02:05.960857 IP6 2600:6ce4:0:208::8.34523 > 2600:6ce4:0:42::132.69: TFTP,
length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg" octet
blksize 1428 tsize 0

20:02:06.692774 IP6 2600:6ce4:0:208::35.36573 > 2600:6ce4:0:42::132.69:
TFTP, length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg"
octet blksize 1428 tsize 0

20:02:10.619007 IP6 2600:6ce4:0:208::29.39632 > 2600:6ce4:0:42::132.69:
TFTP, length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg"
octet blksize 1428 tsize 0

20:02:11.693711 IP6 2600:6ce4:0:208::10.48226 > 2600:6ce4:0:42::132.69:
TFTP, length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg"
octet blksize 1428 tsize 0

20:02:12.474559 IP6 2600:6ce4:0:208::1b.46737 > 2600:6ce4:0:42::132.69:
TFTP, length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg"
octet blksize 1428 tsize 0

20:02:12.974028 IP6 2600:6ce4:0:208::18.43246 > 2600:6ce4:0:42::132.69:
TFTP, length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg"
octet blksize 1428 tsize 0

20:02:13.018275 IP6 2600:6ce4:0:208::5.54250 > 2600:6ce4:0:42::132.69: TFTP,
length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg" octet
blksize 1428 tsize 0

20:02:13.082634 IP6 2600:6ce4:0:208::f.51793 > 2600:6ce4:0:42::132.69: TFTP,
length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg" octet
blksize 1428 tsize 0

20:02:14.953996 IP6 2600:6ce4:0:208::d.40428 > 2600:6ce4:0:42::132.69: TFTP,
length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg" octet
blksize 1428 tsize 0

20:02:16.716193 IP6 2600:6ce4:0:208::28.55492 > 2600:6ce4:0:42::132.69:
TFTP, length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg"
octet blksize 1428 tsize 0

20:02:17.513615 IP6 2600:6ce4:0:208::21.37665 > 2600:6ce4:0:42::132.69:
TFTP, length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg"
octet blksize 1428 tsize 0

20:02:17.842297 IP6 2600:6ce4:0:208::31.35849 > 2600:6ce4:0:42::132.69:
TFTP, length 83, RRQ "WBDocCfg166_erouter6_no_nat_usp_v5_commscope_cert.cfg"
octet blksize 1428 tsize 0

 

I attempted that a few times with no success. I also ran packet captures and
the DHCPv6 packets do show only the global config-file value, irrespective
of the override for the specific prefix. 

 

Is this an expected behavior or am I hitting some known bug? I did review
the documentation and it seems to imply that the override should work
without any problems. Is there anything I am missing in the config to force
the override to work?

 

Regards

 

Marek

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.isc.org/pipermail/kea-users/attachments/20240503/f858b6cf/attachment-0001.htm>


More information about the Kea-users mailing list