Topology
.
Figure 9-16: DHCPv6 Relay Delegating Configuration
DHCP Relay - Delegating Router (DR)
#configure terminal | Enter configure mode. |
(config)#feature dhcp | Enable the feature DHCP. This is enabled by default. |
(config)#ipv6 dhcp relay | By default, this will be enabled. It starts the IPv6 DHCP relay service. |
(config)#ipv6 dhcp relay address 2001:101:0:1::131 | The relay address configured should be server interface address connected to Delegating Router. |
(config)#interface ce1/2 | Enter interface mode. |
(config-if)#ipv6 address 2001:101:0:1::130/64 | Configure IPv6 address on the interface ce1/2 |
(config-if)#ipv6 dhcp relay uplink | Configure relay uplink on the device connecting the server. |
(config-if)#exit | Exit interface mode. |
(config)#commit | Commit the candidate configuration to the running configuration |
(config)#interface ce16/1 | Enter interface mode. |
(config-if)#ipv6 address 3001:101:0:1::135/64 | Configure IPv6 address on the interface ce16/1 |
(config-if)#ipv6 dhcp relay | Relay should be configured on the interface connecting to the client. |
(config-if)#exit | Exit interface mode. |
(config)#commit | Commit the candidate configuration to the running configuration |
(config)#ipv6 dhcp relay pd-route-injection | Configure to enable auto route injection. |
Requesting Router (RR)
#configure terminal | Enter configure mode. |
(config)#interface ce16/1 | Enter interface mode. |
(config-if)#ipv6 address dhcp | Configure IPv6 address DHCP. |
(config-if)#ipv6 dhcp prefix-delegation PREFIX_FROM_SERVER | Configure IPv6 DHCP prefix-delegation |
(config-if)#exit | Exit interface mode. |
(config)#commit | Commit the candidate configuration to the running configuration |
(config)#interface ce23/1 | Enter interface mode. |
(config-if)#ipv6 address PREFIX_FROM_SERVER ::1:0:0:0:1/64 | Configure IPv6 address from the prefix learnt |
(config-if)#ipv6 nd ra-interval 4 | Configure ra-interval |
(config-if)#exit | Exit interface mode. |
(config)#ipv6 route 2001:101:0:1::/64 3001:101:0:1::135 | Configure static route towards server |
(config)#commit | Commit the candidate configuration to the running configuration |
HOST
#configure terminal | Enter configure mode. |
(config)#interface ce23/1 | Enter interface mode. |
(config-if)#ipv6 address autoconfig | Configure IPv6 autoconfig |
(config if)#exit | Exit interface mode. |
(config)#ipv6 route 2001:101:0:1::/64 fe80::ce37:abff:fec9:7426 ce23/1 | Configure static route towards server |
(config)#commit | Commit the candidate configuration to the running configuration |
Linux Host
IPV6_AUTOCONF=yes | IPv6 autoconfig should be set to yes in interface config file. |
DHCP Server
ifconfig eth1 inet6 add 2001:101:0:1::131/64 | Configure IPv6 address on client facing interface |
dhcpd -d -6 -cf /etc/dhcp/dhcpd6.conf eth1 | Start server |
ipv6 route 1212:501:102:1::/64 2001:101:0:1::130 | Configure static route towards Requesting Router |
Sample dhcpd6.conf file
#
#DHCPv6 Server Configuration file.
#see /usr/share/doc/dhcp*/dhcpd6.conf.sample
#see dhcpd.conf(5) man page
#
preferred-lifetime 400;
default-lease-time 600;
subnet6 2001:101:0:1::/64 {
range6 2001:101:0:1::129 2001:101:0:1::254;
}
subnet6 3001:101:0:1::/64 {
range6 3001:101:0:1::129 3001:101:0:1::254;
prefix6 1212:501:101:: 1212:501:102:: /48;
option dhcp6.name-servers fec0:0:0:1::1;
option dhcp6.domain-search "domain.example";
}
Validation
Delegation Router (DR)
DR#sh ipv6 dhcp relay
IPv6 DHCP relay service is Enabled.
VRF Name: default
DHCPv6 Servers configured: 2001:101:0:1::131
DHCPv6 IA_PD Route injection: Enabled
Interface Uplink/Downlink
--------- -------------
ce1/2 Downlink
ce16/1 Uplink
DR#sh ipv6 route
IPv6 Routing Table
Codes: K - kernel route, C - connected, S - static, D- DHCP, R - RIP,
O - OSPF, IA - OSPF inter area, E1 - OSPF external type 1,
E2 - OSPF external type 2, E - EVPN N1 - OSPF NSSA external type 1,
N2 - OSPF NSSA external type 2, i - IS-IS, B - BGP
Timers: Uptime
IP Route Table for VRF "default"
C ::1/128 via ::, lo, 19:24:04
D 1212:501:102::/48 [80/0] via fe80::eac5:7aff:fe64:4a20, ce16/1, 00:00:01
C 2001:101:0:1::/64 via ::, xe4, 03:42:58
C 3001:101:0:1::/64 via ::, xe2, 02:51:04
C 4001:101:0:1::/64 via ::, xe5, 03:14:41
C fe80::/64 via ::, xe9, 00:41:39
#sh ipv6 dhcp pd-route
VRF : default
1212:501:102::/48 via fe80::eac5:7aff:fe64:4a20, ce16/1, (2019-05-30 14:02:50 - 2
019-05-30 14:04:50)
Requesting Router (RR)
RR#show ipv6 dhcp interface
ce16/1 is in client mode
prefix name: PREFIX_FROM_SERVER1
learned prefix: 1212:501:102::/48
preferred lifetime 600, valid lifetime 600
interfaces using the learned prefix
ce23/1 1212:501:102:1::1
RR#sh ipv6 interface ce23/1 brief
Interface IPv6-Address Admin-Status
Ce23/1 *1212:501:102:1::1
fe80::ce37:abff:fec9:7426 [up/up]
RR#show int ce23/1
Interface ce23/1
Scope: both
Flexport: Breakout Control Port (Active): Break Out Enabled
Hardware is ETH Current HW addr: cc37.abc9.7426
Physical:cc37.abc9.743f Logical:(not set)
Port Mode is Router
Interface index: 10025
Metric 1 mtu 1500 duplex-full link-speed 1g
Debounce timer: disable
<UP,BROADCAST,RUNNING,MULTICAST>
VRF Binding: Not bound
DHCP client is disabled.
Last Flapped: 2021 Mar 02 09:44:05 (00:03:55 ago)
Statistics last cleared: 2021 Mar 02 09:44:05 (00:03:55 ago)
inet6 1212:501:102:1::1/64
inet6 fe80::ce37:abff:fec9:7426/64
ND router advertisements are sent approximately every 571 seconds
ND next router advertisement due in 434 seconds.
ND router advertisements live for 1800 seconds
Hosts use stateless autoconfig for addresses.
5 minute input rate 2 bits/sec, 0 packets/sec
5 minute output rate 23 bits/sec, 0 packets/sec
HOST
[root@localhost ~]#ifconfig -a
eth3 Link encap:Ethernet HWaddr 00:07:E9:A5:23:4C
inet6 addr: 1212:501:102:1:207:e9ff:fea5:234c/64 Scope:Global
inet6 addr: fe80::207:e9ff:fea5:234c/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:196985 errors:0 dropped:0 overruns:0 frame:0
TX packets:5733 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:23542362 (22.4 MiB) TX bytes:710558 (693.9 KiB)
N4#show ipv6 interface xe7 brief
Interface IPv6-Address Admin-Status
ce23/1 *1212:501:102:1:6821:5fff:fe55:4a27
fe80::6a21:5fff:fe55:4a27 [up/up]
Last modified date: 10/19/2023