apparently sometimes users have problems reaching outside internet with some network setups. this is the workaround a user suggested that we should add in the wiki.
Signed-off-by: Oguz Bektas <o.bek...@proxmox.com> --- v1->v2: * add more rationale as suggested by stoiko * fix indent on one line in the example config * add links stoiko posted in mailing list for reference pve-network.adoc | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/pve-network.adoc b/pve-network.adoc index c61cd42..1913498 100644 --- a/pve-network.adoc +++ b/pve-network.adoc @@ -243,11 +243,29 @@ iface vmbr0 inet static bridge_stp off bridge_fd 0 - post-up echo 1 > /proc/sys/net/ipv4/ip_forward + post-up echo 1 > /proc/sys/net/ipv4/ip_forward post-up iptables -t nat -A POSTROUTING -s '10.10.10.0/24' -o eno1 -j MASQUERADE post-down iptables -t nat -D POSTROUTING -s '10.10.10.0/24' -o eno1 -j MASQUERADE ---- +NOTE: In some masquerade setups with firewall enabled, conntrack zones might be +needed for outgoing connections. Otherwise the firewall could block outgoing +connections since they will prefer the `POSTROUTING` of the VM bridge (and not +`MASQUERADE`). + +Adding these lines in the `/etc/network/interfaces` can fix this problem: + +---- +post-up iptables -t raw -I PREROUTING -i fwbr+ -j CT --zone 1 +post-down iptables -t raw -D PREROUTING -i fwbr+ -j CT --zone 1 +---- + +For more information about this, refer to the following links: +https://commons.wikimedia.org/wiki/File:Netfilter-packet-flow.svg[Netfilter Packet Flow] +https://lwn.net/Articles/370152/[Patch on netdev-list introducing conntrack zones] +https://blog.lobraun.de/2019/05/19/prox/[Blog post with a good explanation by using TRACE in the raw table] + + Linux Bond ~~~~~~~~~~ -- 2.20.1 _______________________________________________ pve-devel mailing list pve-devel@pve.proxmox.com https://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel