Comcast/DHCPv6-PD problems with 5.19

RouterOS General
1

Hi,

I’m having problems getting DHCPv6-PD working with Comcast’s pilot IPv6 deployment. Running 5.19 on a RB2011.

Here’s what my config looks like:

/ipv6 address
add address=::1/64 advertise=yes disabled=no eui-64=no interface=bridge-local
/ipv6 dhcp-client
add add-default-route=yes disabled=no interface=ether1-gateway pool-name=\
    comcast-ipv6 pool-prefix-length=64
/ipv6 nd
set [ find default=yes ] advertise-dns=no advertise-mac-address=yes disabled=\
    no hop-limit=unspecified interface=all managed-address-configuration=no \
    mtu=unspecified other-configuration=no ra-delay=3s ra-interval=3m20s-10m \
    ra-lifetime=30m reachable-time=unspecified retransmit-interval=\
    unspecified
/ipv6 nd prefix default
set autonomous=yes preferred-lifetime=1w valid-lifetime=4w2d

With 5.19, the problem with multiple DHCPv6 servers (described in this thread has been resolved, but there are now two problems keeping me from getting this working properly.

First, when I set add-default-route=yes inside of /ipv6 dhcp-client, the route that gets added is not a default route, but instead a static route for the /64 assigned by PD. The gateway is correct, though (LL address for the CMTS).

[admin@MikroTik] /ipv6 route> print detail
Flags: X - disabled, A - active, D - dynamic, 
C - connect, S - static, r - rip, o - ospf, b - bgp, U - unreachable 
 0 ADS  dst-address=2601:9:XXXX:XXXX::/64 
        gateway=fe80::XXXX:XXff:feXX:XXXX%ether1-gateway 
        gateway-status=fe80::XXXX:XXff:feXX:XXXX%ether1-gateway reachable 
        distance=1 scope=30 target-scope=10

Second, no matter what I try, the from-pool parameter on /ipv6 interface does not seem to stick. It’s accepted by the CLI, and I can’t choose a pool that doesn’t exist, but the parameter does not show up in the status output:

[admin@MikroTik] /ipv6 address> print detail
Flags: X - disabled, I - invalid, D - dynamic, G - global, L - link-local 
[...]
 3 IG address=::1/64 interface=bridge-local actual-interface=bridge-local 
      eui-64=no advertise=yes 

[admin@MikroTik] /ipv6 address> set 3 from-pool=comcast-ipv6 

[admin@MikroTik] /ipv6 address> print detail
Flags: X - disabled, I - invalid, D - dynamic, G - global, L - link-local 
[...]
 3 IG address=::1/64 interface=bridge-local actual-interface=bridge-local 
      eui-64=no advertise=yes

Notice that “from-pool” still isn’t showing up in the config. I have removed the config, rebooted, readded, disabled dhcp-client, reenabled dhcp-client… etc.

Comcast is giving me a /64 via PD and the pool prefix length I am handing out is set to 64, so perhaps the dhcpv6 client is getting confused at only having one prefix to hand out?

[admin@MikroTik] /ipv6 dhcp-client> print detail
Flags: D - dynamic, X - disabled, I - invalid 
 0    interface=ether1-gateway pool-name="comcast-ipv6" pool-prefix-length=64 
      status=bound prefix=2601:9:XXXX:XXXX::/64 expires-after=23h25m34s 
      duid="xxxxxxxxxxxxxxxxxxxx" add-default-route=yes

Any ideas?

DHCPv6 for home installations?
2

FWIW, I haven’t been able to get my RB750GL (5.19) working on Comcast either (it’s not a pilot anymore, it’s production).

I put on a D-Link (DIR-655 B1) or Netgear (WNR3500Lv2) router and Native Dual-Stack IPv6 works just fine.

The RB is getting the IPv6 prefix, RA’s are sent on the LAN and hosts addressed using the prefix, and I can see the LL address of the CMTS, but I cannot route out. A trace from the host shows the packets being sent to the RB where they die.

3

As you can read in these posts (http://forum.mikrotik.com/t/dhcpv6-for-home-installations/55717/1), this problem was widely discussed, classified as a bug, and we have mikrotik’s statement that it will be solved in the next release.

Until then, remove the “add-default-route=yes” from your IPv6 dhcp client and set your default gateway by hand:

/ipv6 route add dst-address=::/0 gateway=fe80::[EUI-64 of ISP router]%ext-if
4

Default route problem will be fixed in v5.20.

As for from-pool parameter, currently it works only in winbox. Do not use it in console.

5

Verified resolved in v5.20.

Thanks!