lxcコンテナはホストをpingしてDNSインターネットアドレスを確認できますが、インターネットにアクセスすることはできません。

Debian Buster amd64
両方のコンテナは 192.168.122.2,3 を確認できますが、インターネットにアクセスできません。
どちらのコンテナもホストサーバーとping/相互作用できます。
これがiptablesにあるものです。

# Generated by xtables-save v1.8.2 on Sat Mar  6 17:16:16 2021  
*filter  
  
:INPUT ACCEPT [47377:13690982]  

:FORWARD ACCEPT [419:628058]  

:OUTPUT ACCEPT [24929:4008372]  

:POSTROUTING - [0:0]  
-A INPUT -p tcp -m tcp --dport 80 -j ACCEPT  
-A INPUT -p tcp -m tcp --dport 443 -j ACCEPT  

-A INPUT -p tcp -m tcp --dport 8080 -j ACCEPT  
-A INPUT -p tcp -m tcp --dport 4430 -j ACCEPT  
-A INPUT -i virbr0 -p udp -m udp --dport 53 -j ACCEPT  
-A INPUT -i virbr0 -p tcp -m tcp --dport 53 -j ACCEPT  
-A INPUT -i virbr0 -p udp -m udp --dport 67 -j ACCEPT  
-A INPUT -i virbr0 -p tcp -m tcp --dport 67 -j ACCEPT  
-A FORWARD -d 192.168.122.2/32 -p tcp -m tcp --dport 80 -j ACCEPT  
-A FORWARD -d 192.168.122.2/32 -p tcp -m tcp --dport 443 -j ACCEPT  
-A FORWARD -d 192.168.122.3/32 -p tcp -m tcp --dport 8080 -j ACCEPT  
-A FORWARD -d 192.168.122.3/32 -p tcp -m tcp --dport 4430 -j ACCEPT  
-A FORWARD -d 192.168.122.0/24 -o virbr0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT  
-A FORWARD -s 192.168.122.0/24 -i enxd03745c9b08e -j ACCEPT  
COMMIT  
# Completed on Sat Mar  6 17:16:16 2021  
# Generated by xtables-save v1.8.2 on Sat Mar  6 17:16:16 2021  
*nat  
:PREROUTING ACCEPT [2101:142603]  
:INPUT ACCEPT [1480:106813]  
:POSTROUTING ACCEPT [430:29500]  
:OUTPUT ACCEPT [329:23520]  
-A PREROUTING -i enxd03745c9b08e -p tcp -m tcp --dport 80 -j DNAT --to-destination  192.168.122.2:80  
-A PREROUTING -i enxd03745c9b08e -p tcp -m tcp --dport 80 -j DNAT --to-destination 192.168.122.2:80  
-A PREROUTING -i enxd03745c9b08e -p tcp -m tcp --dport 443 -j DNAT --to-destination  192.168.122.2:443  
-A PREROUTING -i enxd03745c9b08e -p tcp -m tcp --dport 8080 -j DNAT --to-destination 192.168.122.3:8080  
-A PREROUTING -i enxd03745c9b08e -p tcp -m tcp --dport 4430 -j DNAT --to-destination 192.168.122.3:4430  
COMMIT  
# Completed on Sat Mar  6 17:16:16 2021  
# Generated by xtables-save v1.8.2 on Sat Mar  6 17:16:16 2021  
*mangle  
:PREROUTING ACCEPT [49751:14725298]  
:INPUT ACCEPT [47442:13695764]  
:FORWARD ACCEPT [1555:987308]  
:OUTPUT ACCEPT [24929:4008372]  
:POSTROUTING ACCEPT [26484:4995680]  
COMMIT  
# Completed on Sat Mar  6 17:16:16 2021