Re: IOS DHCP IPV6 TFTP for IP Phone

CCIE7700 · ‎09-01-2017

I could not find any documentation as to what vender specic ID (Enterprise ID) to use for providing and IP Phone with a IPV6 TFTP Server via DHCP. This is the equivelent of Option 150 in IPV4.

I did find a post that showed it, but the post was talking about something else.

ipv6 dhcp pool "poolname"

address prefix x:x:x:x::/64

dns-server x:x:x:x

domain-name name.com

!Here is the option 150 Equivelent for IPV6

vendor-specific 9

!Address of TFTP Server

suboption 1 address x:x:x:x:x:x:x:x

Under the interface

int x/x

ipv6 address x:x:x:x:x:x:x:x

ipv6 enable

ipv6 nd other-config-flag

ipv6 dhcp server poolname

Phillip Remaker · ‎09-11-2017

Page 54 of https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/uc_system/IPv6/vtgs_b_ipv6-deployment-guide-for-cisco.pdf should be useful.

Specific relevant sample config from the doc. "vendor-specific 9" is the TFTP server.

The following example shows the configuration for a Cisco IOS IPv6 DHCP server.
! Activate DHCP Service on the IOS Device service dhcp
!
! Specify the name of this specific IPv6 DHCP pool, the address prefix and lifetime, the
link address and
! vendor-specific option and sub option with TFTP server address(es) ipv6 dhcp pool
v6-CLUSTER-B
address prefix 2001:101:2:1::/64 lifetime 172800 86400 link-address 2001:101:2:1::/64
vendor-specific 9
suboption 1 address 2001:101:2::10 2001:101:2::11

If you want to use RFC 2872 "service names" instead, I believe you can use suboption 2 but I have not tested.