Cogeco fiber (Sagemcom Fast 5681V passthrough): DHCPv6 address OK, but no RAs and no prefix delegation
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I'm trying to get native IPv6 working on Cogeco fiber (Canada) and I'm stuck. I'd appreciate any pointers, especially from other Cogeco users.
Setup
pfSense Plus 26.07-RELEASE on a Netgate SG-4860
Cogeco fiber, Sagemcom Fast 5681V in IP passthrough mode, connected directly to pfSense (no ISP router in between)
WAN: IPv4 via DHCP works fine (public address, ~900/900)
WAN IPv6: DHCP6, prefix delegation size /56, "Send IPv6 prefix hint" checkedWhat works
DHCPv6 assigns a global /128 address on the WAN (in 2001:1970:4004:41d::/64), and IPv6 DNS servers are received.
What doesn't
No IPv6 default route, and the DHCP6 gateway stays "Pending."
No prefix is delegated: /tmp/igb2_pdinfo doesn't exist.
No router advertisements are received on the WAN, solicited or unsolicited.What I've checked
rtsol -d igb2 reports "No answer after sending 3 RSs" (with accept_rtadv confirmed set on the interface).
A packet capture on the WAN during rtsol shows three router solicitations going out to ff02::2, and nothing coming back:
IP6 fe80::208:a2ff:fe0f:6f33 > ff02::2: ICMP6, router solicitation, length 16
IP6 fe80::208:a2ff:fe0f:6f33 > ff02::2: ICMP6, router solicitation, length 16
IP6 fe80::208:a2ff:fe0f:6f33 > ff02::2: ICMP6, router solicitation, length 16
The built-in ICMPv6 pass rules for RS/RA (fe80::/10
ff02::/16) are present in pfctl -sr, so the firewall isn't dropping RAs.
The old WAN (DSL), which was also sending RAs, has been fully removed, so there's no competing IPv6 interface.There doesn't seem to be a management interface that I can get to on the sagemcom modem, everything seems locked down.
Cogeco's response
Tier 2 support escalated the question internally. The answer was that:- ipv6 works,
- I should use the Cogeco supplied router and be happy,
- they only support their own equipment, there were no settings they could change on their end,
- and that I should ask Netgate.
Questions
Has anyone gotten native IPv6 with prefix delegation working on Cogeco fiber with their own router? If so, which DHCP6 settings did you use?
Is the Sagemcom 5681V known to pass IPv4 through but not forward RAs or PD to a downstream router in passthrough mode? Is there a modem-side setting for this?
Anything else I should check on the pfSense side? -
@tmoore said in Cogeco fiber (Sagemcom Fast 5681V passthrough): DHCPv6 address OK, but no RAs and no prefix delegation:
ipv6 works,
I should use the Cogeco supplied router and be happy,
they only support their own equipment, there were no settings they could change on their end,You cannot expect them to support anything they don't own. Do things work properly with their own modem? What does Wirestark or other packet capture say? That would show if there is a RA and it's contents.
A few years ago, I had a problem with Rogers where the RA did not match the network. Despite extensive testing that showed they were at fault, they wouldn't do anything. Finally, they sent a senior tech and even with his own computer and modem had the same problem. He then went back to the office and tried 4 different CMTS. Only the one I was connected to didn't work. The problem was finally resolved.
Here is what Wireshark showed:
Frame 29: 214 bytes on wire (1712 bits), 214 bytes captured (1712 bits)
on interface 0
Ethernet II, Src: Casa_9a:a1:99 (00:17:10:9a:a1:99), Dst:
Trendnet_2b:ed:ea (00:14:d1:2b:ed:ea)
Internet Protocol Version 6, Src: fe80::217:10ff:fe9a:a199, Dst:
fe80::214:d1ff:fe2b:edea
User Datagram Protocol, Src Port: 547, Dst Port: 546
DHCPv6
Message type: Reply (7)
Transaction ID: 0x18a8e9
Client Identifier
Option: Client Identifier (1)
Length: 14
Value: 0001000123eb5e12001617a7f2d3
DUID: 0001000123eb5e12001617a7f2d3
DUID Type: link-layer address plus time (1)
Hardware type: Ethernet (1)
DUID Time: Feb 4, 2019 15:33:22.000000000 EST
Link-layer address: 00:16:17:a7:f2:d3
Server Identifier
Option: Server Identifier (2)
Length: 14
Value: 00010001159bb6e50021285fd2b7
DUID: 00010001159bb6e50021285fd2b7
DUID Type: link-layer address plus time (1)
Hardware type: Ethernet (1)
DUID Time: Jun 27, 2011 17:47:17.000000000 EDT
Link-layer address: 00:21:28:5f:d2:b7
Identity Association for Prefix Delegation
Option: Identity Association for Prefix Delegation (25)
Length: 72
Value: 000000000000000000000000000d003800064e6f20707265...
IAID: 00000000
T1: 0
T2: 0
Status code
Option: Status code (13)
Length: 56
Value: 00064e6f2070726566697820617661696c61626c65206f6e...
Status Code: NoPrefixAvail (6)
Status Message: No prefix available on LinkNote the message about no prefix available. This indicates the problem originated with the CMTS I was on.
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