Windows Guest with weird internet issues (possible lack of support for http2)

[mike86]

Some of websites will return this:
ERR_HTTP2_PROTOCOL_ERROR

Some others like i.e. Azure DevOps won't load properly login screen with F2A (just err timeouts for js/css).

In case of HTTP2 the host cannot load the content via curl, but in regards to Azure it can load content that failed on guest.

I cannot find too much info about what I supposed to add to allow everything working perfectly fine as on bare metal windows machine (same links are working on other machines/vmware).
It is proxmox 7, few days old (I am trying to move from esxi)

Here is my network config (firewalls are disabled)

auto lo
iface lo inet loopback

iface lo inet6 loopback

auto eno1
iface eno1 inet manual
        up route add -net XXXXXXX

netmask 255.255.255.224
gw XXXXXXX dev eno1
# route XXXXXX/27 via XXXXXXXX

auto eno1.4000
iface eno1.4000 inet manual
        mtu 1400

iface eth0 inet manual

auto vmbr0
iface vmbr0 inet static
        address XXXXXXX/27
        gateway XXXXXXX
        bridge-ports eno1
        bridge-stp off
        bridge-fd 0

auto vmbr1
iface vmbr1 inet static
        address 10.254.254.254/8
        bridge-ports none
        bridge-stp off
        bridge-fd 0
        post-up echo 1 > /proc/sys/net/ipv4/ip_forward
        post-up iptables -t nat -A POSTROUTING -s '10.0.0.0/8' -o vmbr0 -j MASQUERADE
        post-up iptables -A POSTROUTING -t nat -s 10.0.0.0/8 -j MASQUERADE
        post-down iptables -t nat -D POSTROUTING -s '10.0.0.0/8' -o vmbr0 -j MASQUERADE


auto vmbr2
iface vmbr2 inet static
        address 192.168.0.100/8
        bridge-ports eno1.4000
        bridge-stp off
        bridge-fd 0