Bug 241792
| Summary: | dhclient/dhclient-script: dhclient default route not working when given a /32 netmask | ||
|---|---|---|---|
| Product: | Base System | Reporter: | sigsys |
| Component: | bin | Assignee: | freebsd-bugs (Nobody) <bugs> |
| Status: | Closed FIXED | ||
| Severity: | Affects Many People | CC: | bz, dch, emaste, pat |
| Priority: | --- | Keywords: | patch |
| Version: | 12.1-RELEASE | ||
| Hardware: | Any | ||
| OS: | Any | ||
|
Description
sigsys
2019-11-07 21:44:40 UTC
I have seen this in Google Cloud, Packet.net and other infrastructures. In the first case Google patched their DHCP setup to accommodate this. In the past I have manually overridden this using settings in dhclient.conf. Patch seems reasonable to me. I thought Linux used to simply arp for an off-link gateway and then use it. I've seen this elsewhere as well with recovery images and documentation, e.g., https://wiki.hetzner.de/index.php/Cloud_IP_static#FreeBSD for static configuration. While I don't do much IPv4 anymore, it seems a proper workaround. +1 on the idea of the change (not reviewed). A commit in branch main references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=fd6ecc184dbc64b9b3f7866b34812fb93df62925 commit fd6ecc184dbc64b9b3f7866b34812fb93df62925 Author: Kristof Provost <kp@FreeBSD.org> AuthorDate: 2022-10-05 10:11:07 +0000 Commit: Kristof Provost <kp@FreeBSD.org> CommitDate: 2022-10-05 10:24:31 +0000 dhclient-script: cope with /32 address leases On certain cloud platforms (Google Cloud, Packet.net and others) the DHCP server offers a /32 address. This makes adding the default route fail since it is not reachable via any interface. Linux's dhclient-script seem to usually have a special case for that and explicitly adds an interface route to the router's address. FreeBSD's dhclient-script already has a special case for when the router address is the same as the leased address. Now also add one for when it's a different address that doesn't fall in the interface's subnet. PR: 241792 Event: Aberdeen hackathon 2022 Submitted by: sigsys@gmail.com Reviewed by: dch, kp, bz (+1 on the idea, not reviewed), thj MFC after: 1 week sbin/dhclient/dhclient-script | 4 ++++ 1 file changed, 4 insertions(+) fwiw I have run 13.1 on GCP, AWS, and Vultr, all without networking issues. I didn’t use pre-built images that might accommodate this issue - on AWS and GCP I extracted base.txz and kernel.txz, and on Vultr I used an ISO disk install. I can’t weigh in on the details of the patch, I can only point out that it might make assumptions that haven’t matched our experience running 13.1 on multiple cloud providers. Yes. I remember that Google had to make changes to accommodate this, as have other cloud vendors. Having a working default network is always handy. A commit in branch stable/12 references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=7ca75b93b9facd6dd0a733f25f577a1c9862a46b commit 7ca75b93b9facd6dd0a733f25f577a1c9862a46b Author: Kristof Provost <kp@FreeBSD.org> AuthorDate: 2022-10-05 10:11:07 +0000 Commit: Kristof Provost <kp@FreeBSD.org> CommitDate: 2022-10-13 07:56:50 +0000 dhclient-script: cope with /32 address leases On certain cloud platforms (Google Cloud, Packet.net and others) the DHCP server offers a /32 address. This makes adding the default route fail since it is not reachable via any interface. Linux's dhclient-script seem to usually have a special case for that and explicitly adds an interface route to the router's address. FreeBSD's dhclient-script already has a special case for when the router address is the same as the leased address. Now also add one for when it's a different address that doesn't fall in the interface's subnet. PR: 241792 Event: Aberdeen hackathon 2022 Submitted by: sigsys@gmail.com Reviewed by: dch, kp, bz (+1 on the idea, not reviewed), thj MFC after: 1 week (cherry picked from commit fd6ecc184dbc64b9b3f7866b34812fb93df62925) sbin/dhclient/dhclient-script | 4 ++++ 1 file changed, 4 insertions(+) A commit in branch stable/13 references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=80e991888d79e036c03461d8264eea08a1dc67d8 commit 80e991888d79e036c03461d8264eea08a1dc67d8 Author: Kristof Provost <kp@FreeBSD.org> AuthorDate: 2022-10-05 10:11:07 +0000 Commit: Kristof Provost <kp@FreeBSD.org> CommitDate: 2022-10-13 07:56:54 +0000 dhclient-script: cope with /32 address leases On certain cloud platforms (Google Cloud, Packet.net and others) the DHCP server offers a /32 address. This makes adding the default route fail since it is not reachable via any interface. Linux's dhclient-script seem to usually have a special case for that and explicitly adds an interface route to the router's address. FreeBSD's dhclient-script already has a special case for when the router address is the same as the leased address. Now also add one for when it's a different address that doesn't fall in the interface's subnet. PR: 241792 Event: Aberdeen hackathon 2022 Submitted by: sigsys@gmail.com Reviewed by: dch, kp, bz (+1 on the idea, not reviewed), thj MFC after: 1 week (cherry picked from commit fd6ecc184dbc64b9b3f7866b34812fb93df62925) sbin/dhclient/dhclient-script | 4 ++++ 1 file changed, 4 insertions(+) |
