Is there a way to trigger pfSense to periodically send RS on WAN I/F to ISP edge router?

Derelict

Why do we care about DHCP? The gateways are not set using DHCP in IPv6.

bimmerdriver

@Derelict If I posted the RS/RA, someone would be asking to see the DHCP messages, so I intended to post them in sequence.

Derelict

DHCP doesn't matter here. Has nothing whatsoever to do with your ISP not sending RAs as required.

bimmerdriver

Here are the RS/RA messages, if the spam filter will allow it.

Internet Control Message Protocol v6
    Type: Router Solicitation (133)
    Code: 0
    Checksum: 0x2efd [correct]
    [Checksum Status: Good]
    Reserved: 00000000
    ICMPv6 Option (Source link-layer address : 00:15:5d:01:49:02)
        Type: Source link-layer address (1)
        Length: 1 (8 bytes)
        Link-layer address: Microsof_01:49:02 (00:15:5d:01:49:02)

Internet Control Message Protocol v6
    Type: Router Advertisement (134)
    Code: 0
    Checksum: 0x74bd [correct]
    [Checksum Status: Good]
    Cur hop limit: 64
    Flags: 0x00, Prf (Default Router Preference): Medium
    Router lifetime (s): 5400
    Reachable time (ms): 0
    Retrans timer (ms): 0
    ICMPv6 Option (Source link-layer address : 0a:b2:58:47:a2:e4)
        Type: Source link-layer address (1)
        Length: 1 (8 bytes)
        Link-layer address: 0a:b2:58:47:a2:e4 (0a:b2:58:47:a2:e4)

Derelict

It has already been established that the ISP responds to an RS with an RA. They need to send periodic RAs and they are not. So that does no good either.

Derelict

You're only at a "karma of three (now 4)" someone else give a so he's over 5. That's more for editing profiles, etc but it can't hurt.

bimmerdriver

@Derelict said in Is there a way to trigger pfSense to periodically send RS on WAN I/F to ISP edge router?:

It has already been established that the ISP responds to an RS with an RA. They need to send periodic RAs and they are not. So that does no good either.

Yes, understood. I'm wondering why pfSense sometimes works in this situation and other times doesn't. As far as I understand, based on correspondence with the ISP, the juniper routers DO NOT send unsolicited RA messages. Shouldn't pfSense always drop the default route after 5400 seconds?

Derelict

They HAVE to send an unsolicited, periodic RA. If juniper has that setting then it is to be used in cases where it is not necessary. This is not a pfSense problem. It is an ISP problem. See RFC4861. The host device is FORBIDDEN from sending another RS unless its interface is shut/no shut, etc.

Derelict

@bimmerdriver

@bimmerdriver said in Is there a way to trigger pfSense to periodically send RS on WAN I/F to ISP edge router?:

@Derelict said in Is there a way to trigger pfSense to periodically send RS on WAN I/F to ISP edge router?:

It has already been established that the ISP responds to an RS with an RA. They need to send periodic RAs and they are not. So that does no good either.

Yes, understood. I'm wondering why pfSense sometimes works in this situation and other times doesn't. As far as I understand, based on correspondence with the ISP, the juniper routers DO NOT send unsolicited RA messages. Shouldn't pfSense always drop the default route after 5400 seconds?

I don't understand your point. ISPs that work and adhere to standards send periodic RAs.

johnpoz

@bimmerdriver said in Is there a way to trigger pfSense to periodically send RS on WAN I/F to ISP edge router?:

far as I understand, based on correspondence with the ISP, the juniper routers DO NOT send unsolicited RA messages.

Says who? 2 second google
https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/no-unsolicited-ra-edit-enhanced-universal-edge-overrides.html

So they have that SET!!! Per previous comments, etc. as well

Says that the DEFAULT is to send them..

Disable the default transmission and periodic refresh of unsolicited Router Advertisement messages by the router when the subscriber interface is created, and at configured periodic intervals thereafter. When you include the no-unsolicited-ra statement, the router sends Router Advertisement messages and associated periodic refresh messages only when it receives a Router Solicitation message from the subscriber.

BTW - that link is first hit on google for "juniper routers unsolicited RA"

Couple hits down is your post on the other distro board.. Posting the same link - so you KNOW its not default and that they set it, not that they DO NOT do it...

If the RFC says the host is "forbidden" from sending RS... You think pfsense should break the rfc and send RS anyway, because some ISP doesn't know how to configure their own choice of hardware? To be standard?

Derelict

Based on RFC4861 I cannot see that as ever working unless you have coded your subscriber devices to violate RFC4861 by periodically sending RSs, thus breaking your subscribers' ability to use compliant devices.

johnpoz

Yeah not sure why they added the "option" but prob some feature request for some bigger odd ball network doing odd things, etc.

But it sure is not "default" nor is with the RFCs - so yeah could break a lot of shit..

bimmerdriver

@Derelict My point is that sometimes, pfSense tolerates the absence of RA messages and IPv6 continues to work. Other times, IPv6 drops after a couple of hours. It can be restored by save / apply on the WAN I/F.

Derelict

No, it doesn't. My guess is that when you think it is tolerating it it is really because something has done something to the WAN port that caused another RS to be issued. Could be a down up on WAN for any reason or probably several other things.

A long packet capture would tell the tale there.

Your ISP is broken. They should fix it. At this point I'd try to make an appointment with someone there. VP or higher.

bimmerdriver

@johnpoz said in Is there a way to trigger pfSense to periodically send RS on WAN I/F to ISP edge router?:

@bimmerdriver said in Is there a way to trigger pfSense to periodically send RS on WAN I/F to ISP edge router?:

far as I understand, based on correspondence with the ISP, the juniper routers DO NOT send unsolicited RA messages.

Says who? 2 second google
https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/no-unsolicited-ra-edit-enhanced-universal-edge-overrides.html

So they have that SET!!!

Says that the DEFAULT is to send them..

Disable the default transmission and periodic refresh of unsolicited Router Advertisement messages by the router when the subscriber interface is created, and at configured periodic intervals thereafter. When you include the no-unsolicited-ra statement, the router sends Router Advertisement messages and associated periodic refresh messages only when it receives a Router Solicitation message from the subscriber.

BTW - that link is first hit on google for "juniper routers unsolicited RA"

Couple hits down is your post on the other distro board.. Posting the same link - so you KNOW its not default and that they set it, not that they DO NOT do it...

If the RFC says the host is "forbidden" from sending RS... You think pfsense should break the rfc and send RS anyway, because some ISP doesn't know how to configure their own choice of hardware? To be standard?

I have a pcap that ran overnight with no unsolicited RA messages. pfsense was dutifully renewing the DHCP lease, but the link wasn't working. The only RA message in the entire pcap was in reply to the RS message sent from pfsense when the link was started. IPv6 worked for a while when the link started, then dropped and did not restore for the duration of the pcap.

The link to Juniper describing the "feature" is from June 2019. Not likely that very many ISPs will push out an update overnight and I'm not sure it would fix the problem the ISP is having.

RFC 4861 says the following for RA destination address: Typically the Source Address of an invoking Router Solicitation or the all-nodes multicast address.

According to the most recent email I got from the ISP, the CPE only accepts unsolicited RA with unicast destination address. (In my case, with a Nokia edge router, that's what my modem is receiving for both the solicited and unsolicited RA messages.) According to the ISP, the Juniper edge router only sends unsolicited RA with all-nodes multicast address destination. (IMO, it makes sense that it would be multicast for unsolicited RA, no idea why this should be a problem for the CPE.) The CPE doesn't accept this, so it drops the default route and IPv6 drops until something triggers another RS message. For customers who are unlucky and have a Juniper edge router, they don't have working IPv6. The ISP is trying to get Juniper to modify the software to support unicast and they are also looking at modifying the CPE to not expire the default route.

It's a pretty pathetic situation when major companies can't / won't make interoperable network equipment. It's not like IPv6 was invented yesterday.

bimmerdriver

@Derelict said in Is there a way to trigger pfSense to periodically send RS on WAN I/F to ISP edge router?:

No, it doesn't. My guess is that when you think it is tolerating it it is really because something has done something to the WAN port that caused another RS to be issued. Could be a down up on WAN for any reason or probably several other things.

A long packet capture would tell the tale there.

Your ISP is broken. They should fix it. At this point I'd try to make an appointment with someone there. VP or higher.

It may well be the case that something is causing the IPv6 to restart but it's not obvious what that would be. I don't have a pcap that captures IPv6 going back up after going down. There are two completely separate, almost identical hyper-v servers, each running the same version of pfsense, connected to the same fibre interface. On one of them IPv6 is solid. On the other it's unreliable. The pcap is from the unreliable one. Both are connected to the same edge router. We haven't had a chance to run a pcap on the other system.

I really doubt a VP is going to take an appointment with a residential subscriber for a bitch session about their network. lolz

Derelict

@bimmerdriver said in Is there a way to trigger pfSense to periodically send RS on WAN I/F to ISP edge router?:

I have a pcap that ran overnight with no unsolicited RA messages. pfsense was dutifully renewing the DHCP lease, but the link wasn't working. The only RA message in the entire pcap was in reply to the RS message sent from pfsense when the link was started. IPv6 worked for a while when the link started, then dropped and did not restore for the duration of the pcap.

Exactly. Because obtaining a gateway (router) is completely disconnected from DHCP in IPv6.

Everything you describe there is exactly what should happen according to RFC4861.

You should be focusing your efforts on your ISP, not your firewall.

I really doubt a VP is going to take an appointment with a residential subscriber for a bitch session about their network. lolz

If you had your ducks in a row and could quickly demonstrate how his network was WRONG the VP might appreciate it.

According to the ISP, the Juniper edge router only sends unsolicited RA with all-nodes multicast address destination. (IMO, it makes sense that it would be multicast for unsolicited RA, no idea why this should be a problem for the CPE.) The CPE doesn't accept this, so it drops the default route and IPv6 drops until something triggers another RS message. For customers who are unlucky and have a Juniper edge router, they don't have working IPv6. The ISP is trying to get Juniper to modify the software to support unicast and they are also looking at modifying the CPE to not expire the default route.

But is sounds like they already know it. pfSense can do a lot of things but it can't fix a broken ISP. Sorry.

What your ISP needs is someone with the cajones to push the necessary change.

Derelict

4.2. Router Advertisement Message Format

Source Address
MUST be the link-local address assigned to the
interface from which this message is sent.

Destination Address
Typically the Source Address of an invoking Router
Solicitation or the all-nodes multicast address.

That's pretty non-committal and I haven't found anything more authoritative but that says the response to an RS will be unicast to the host sending the RS being responded to and, if unsolicited, it will be to the all-nodes multicast address.

johnpoz

Which makes complete sense - you sure wouldn't want to send out multicast every time someone asks for a RS.. Would just generate noise..

JKnott

@bimmerdriver said in Is there a way to trigger pfSense to periodically send RS on WAN I/F to ISP edge router?:

According to the most recent email I got from the ISP, the CPE only accepts unsolicited RA with unicast destination address.

That's nonsense. Unsolicited RAs only go to the multicast address. If they were only sent to the unicast address, how would the router know the unicast address of something that didn't send a request?