vyos-1x.git/data/templates/dhcp-client, branch rolling

pppoe: T7485: add DHCPv6 options to disable DNS

2025-10-09T15:12:10+00:00

Co-Authored-By: Christian Breunig

T7682: incorrect sla-len in DHCPv6 client prefix delegation (DHCPv6-PD)

2025-09-13T06:55:31+00:00

The current template has an overly optimistic logic for sla-len calculation, relying on an assumption that a server always provides a prefix with the exact length requested by the client. This is incorrect. According to RFC8415 and RFC7084, the prefix length in a request is only a hint for the server, which may decide to provide a different prefix size. The big issue here is that wide-dhcpv6-client uses the sla-len value from the configuration regardless of the received prefix size. This seems to be the known issue. The good news is that we have already inherited a patch from Debian to mitigate the issue [1]. It accomplishes exactly what we are doing in the configuration template, but with the advantage of using the actual prefix length from the received prefix, rather than the one configured in the configuration file. If we simply remove sla-len from the template, everything appears to function normally. Before - server sending /56 set interfaces ethernet eth1 address 'dhcpv6' set interfaces ethernet eth1 dhcpv6-options pd 1 interface eth2 address '1' set interfaces ethernet eth1 dhcpv6-options pd 1 interface eth2 sla-id '0' set interfaces ethernet eth1 dhcpv6-options pd 1 length '60' Resulted in: vyos@vyos# run show interfaces Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down Interface IP Address MAC VRF MTU S/L Description ----------- ------------------- ----------------- ------- ----- ----- ------------- eth1 fc00:0:0:1::200/128 0c:67:94:67:00:01 default 1500 u/u eth2 fc00:0:2:ff00::1/60 0c:67:94:67:00:02 default 1500 u/u Whereas IPv6 PD should always use a /64 prefix on the interface we assign a dynamic DHCPv6 prefix to. After the fix: vyos@vyos:~$ show interfaces Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down Interface IP Address MAC VRF MTU S/L Description ----------- ------------------- ----------------- ------- ----- ----- ------------- eth1 fc00:0:0:1::200/128 0c:67:94:67:00:01 default 1500 u/u eth2 fc00:0:2:ff00::1/64 0c:67:94:67:00:02 default 1500 u/u If a DHCPv6 server (e.g. VyOS itself) even provides multiple PD prefixes, the right one is choosen. Assume the following server configuration: set service dhcpv6-server shared-network-name dhcpv6-1 subnet fc00:0:0:1::/64 address-range start fc00:0:0:1::100 stop 'fc00:0:0:1::200' set service dhcpv6-server shared-network-name dhcpv6-1 subnet fc00:0:0:1::/64 lease-time default '120' set service dhcpv6-server shared-network-name dhcpv6-1 subnet fc00:0:0:1::/64 prefix-delegation start fc00:0:2:: prefix-length '56' set service dhcpv6-server shared-network-name dhcpv6-1 subnet fc00:0:0:1::/64 prefix-delegation start fc00:0:2:: stop 'fc00:0:2:ff00::' set service dhcpv6-server shared-network-name dhcpv6-1 subnet fc00:0:0:1::/64 prefix-delegation start fc00:0:3:: prefix-length '60' set service dhcpv6-server shared-network-name dhcpv6-1 subnet fc00:0:0:1::/64 prefix-delegation start fc00:0:3:: stop 'fc00:0:3:ff00::' If a /56 is requested ("dhcpv6-options pd 1 length 56") - we will get a per interface /64 from the original /56 prefix-delegation from the DHCPv6 server. If the user suddently requests a /60 ("dhcpv6-options pd 1 length 60") the delegated prefix will be from the above fc00:0:3:: pool. 1: https://salsa.debian.org/debian/wide-dhcpv6/-/blob/debian/20080615-23/debian/patches/0021-Make-sla-len-config-optional.patch

dhcpv6-client: T6113: add proper startup/shutdown order for systemd units

2025-04-15T19:20:22+00:00

When running dhcp6c on top of a PPPoE interface, properly honor the dependency chain with systemd. On shutdown we need to stop the wide-dhcpv6-client prior to shutting down the ppp portion of the interface.

dhcpv6-client: T2590: fix vyos-hostsd update for nameserver and search domains

2024-04-01T12:04:50+00:00

After migrating from ISC DHCLIENT for IPv6 to wide-dhcp-client the logic which was present to update /etc/resolv.conf with the DHCP specified nameservers and also the search domain list was no longer present. This commit adds a per interface rendered script to inform vyos-hostsd about the received IPv6 nameservers and search domains.

op-mode: T6175: "renew dhcp interface " does not check for DHCP interface

2024-03-28T06:36:22+00:00

The current op-mode script simply calls sudo systemctl restart "dhclient@$4.service" with no additional information about a client interface at all. This results in useless dhclient processes root 47812 4.7 0.0 5848 3584 ? Ss 00:30 0:00 /sbin/dhclient -4 -d root 48121 0.0 0.0 4188 3072 ? S 00:30 0:00 \_ /bin/sh /sbin/dhclient-script root 48148 50.0 0.2 18776 11264 ? R 00:30 0:00 \_ python3 - Which also assign client leases to all local interfaces, if we receive one valid DHCPOFFER vyos@vyos:~$ show interfaces Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down Interface IP Address MAC VRF MTU S/L Description ----------- ----------------- ----------------- ------- ----- ----- ------------- eth0 - 00:50:56:bf:c5:6d default 1500 u/u eth0.10 172.16.33.102/24 00:50:56:bf:c5:6d default 1500 u/u eth1 172.16.33.131/24 00:50:56:b3:38:c5 default 1500 u/u 172.16.33.102/24 and 172.16.33.131/24 are stray DHCP addresses. This commit moved the renew command to the DHCP op-mode script to properly validate if the interface we request a renew for, has actually a dhcp address configured. In additional this exposes the renew feature to the API.

dhcp-client: T5760: add CLI option to pass user-class parameter

2023-11-19T20:47:31+00:00

Example: set interfaces ethernet eth0 dhcp-options user-class VyOS or set interfaces ethernet eth0 dhcp-options user-class 56:79:4f:53

dhcp-client: T5760: add constraints for dhclient string options

2023-11-19T20:43:15+00:00

The string data type specifies either an NVT ASCII string enclosed in double quotes, or a series of octets specified in hexadecimal, separated by colons. For example: set interfaces ethernet eth0 dhcp-options client-id CLIENT-FOO or set interfaces ethernet eth0 dhcp-options client-id 43:4c:49:45:54:2d:46:4f:4f As of now there was no input validation performed.

Revert: dhcp: T5428: always release lease from default VRF

2023-08-17T11:10:38+00:00

This reverts commit 9afcea251bdc895ffd49cb11f455fd636fdf817b A DHCP relese must also be originated from the VRF where the dhclient program is running, else the RELEASE message can not be send through the interface towards the DHCP server. The reason it did not work in the past was because of https://vyos.dev/T5476

dhcp: T5428: always release lease from default VRF

2023-08-07T21:05:12+00:00

Otherwise packet can be received in a VRF that was already deleted. Image of the following CLI commands: del interface ethernet eth0 address dhcp del interface ethernet eth0 vrf red del vrf name red VRF could be deleted even if dhclient release was not yet completely processed.

dhcpv6: T5428: client renewal fails when running inside VRF

2023-08-05T07:28:35+00:00