Failed to ping external network from linux namespace, why?

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I created a namespace, and used a veth pair(veth1 and veth2) to connect the namespace with my host. I also created a linux bridge in my host and add eth0 and veth1 to the bridge as interfaces. Hers is the commands:



ip netns add namespace2
ip link add veth1 type veth peer name veth2
ip link set veth2 netns namespace2
brctl addbr br1
brctl addif br1 ens33
ifconfig ens33 0.0.0.0
ifconfig br1 192.168.90.43/22 up
brctl addif br1 veth1
ip netns exec namespace2 ifconfig veth2 192.168.90.47/22 up
ip netns exec namespace2 route add default gw 192.168.91.254
iptables -t filter -A FORWARD -m physdev --physdev-in ens33 --physdev-out veth1 -j ACCEPT
iptables -t filter -A FORWARD -m physdev --physdev-out ens33 --physdev-in veth1 -j ACCEPT


When I ping outside from my host, it works



ping 8.8.8.8


But when I ping from my namespace, it fails



ip netns exec namespace2 ping 8.8.8.8


I try to ping my gateway from 



ip netns exec namespace2 ping 192.168.91.254


It has about 70% package loss.



Why it that happen?






linux networking iptables







share|improve this question























  • Well I wrote an answer telling you forgot to bring veth1 up. But then I read about 70% packet loss (when it should have been 100%). So I'm at a loss and deleted the answer
    – A.B
    Aug 20 at 17:47










  • Eventually I found it's about arp for the ip - arp binding was wrong, but I don`t know why it would be wrong.
    – Don_Chen
    Aug 22 at 3:31














up vote
1
down vote

favorite












I created a namespace, and used a veth pair(veth1 and veth2) to connect the namespace with my host. I also created a linux bridge in my host and add eth0 and veth1 to the bridge as interfaces. Hers is the commands:



ip netns add namespace2
ip link add veth1 type veth peer name veth2
ip link set veth2 netns namespace2
brctl addbr br1
brctl addif br1 ens33
ifconfig ens33 0.0.0.0
ifconfig br1 192.168.90.43/22 up
brctl addif br1 veth1
ip netns exec namespace2 ifconfig veth2 192.168.90.47/22 up
ip netns exec namespace2 route add default gw 192.168.91.254
iptables -t filter -A FORWARD -m physdev --physdev-in ens33 --physdev-out veth1 -j ACCEPT
iptables -t filter -A FORWARD -m physdev --physdev-out ens33 --physdev-in veth1 -j ACCEPT


When I ping outside from my host, it works



ping 8.8.8.8


But when I ping from my namespace, it fails



ip netns exec namespace2 ping 8.8.8.8


I try to ping my gateway from 



ip netns exec namespace2 ping 192.168.91.254


It has about 70% package loss.



Why it that happen?






linux networking iptables







share|improve this question























  • Well I wrote an answer telling you forgot to bring veth1 up. But then I read about 70% packet loss (when it should have been 100%). So I'm at a loss and deleted the answer
    – A.B
    Aug 20 at 17:47










  • Eventually I found it's about arp for the ip - arp binding was wrong, but I don`t know why it would be wrong.
    – Don_Chen
    Aug 22 at 3:31












up vote
1
down vote

favorite









up vote
1
down vote

favorite











I created a namespace, and used a veth pair(veth1 and veth2) to connect the namespace with my host. I also created a linux bridge in my host and add eth0 and veth1 to the bridge as interfaces. Hers is the commands:



ip netns add namespace2
ip link add veth1 type veth peer name veth2
ip link set veth2 netns namespace2
brctl addbr br1
brctl addif br1 ens33
ifconfig ens33 0.0.0.0
ifconfig br1 192.168.90.43/22 up
brctl addif br1 veth1
ip netns exec namespace2 ifconfig veth2 192.168.90.47/22 up
ip netns exec namespace2 route add default gw 192.168.91.254
iptables -t filter -A FORWARD -m physdev --physdev-in ens33 --physdev-out veth1 -j ACCEPT
iptables -t filter -A FORWARD -m physdev --physdev-out ens33 --physdev-in veth1 -j ACCEPT


When I ping outside from my host, it works



ping 8.8.8.8


But when I ping from my namespace, it fails



ip netns exec namespace2 ping 8.8.8.8


I try to ping my gateway from 



ip netns exec namespace2 ping 192.168.91.254


It has about 70% package loss.



Why it that happen?






linux networking iptables







share|improve this question















I created a namespace, and used a veth pair(veth1 and veth2) to connect the namespace with my host. I also created a linux bridge in my host and add eth0 and veth1 to the bridge as interfaces. Hers is the commands:



ip netns add namespace2
ip link add veth1 type veth peer name veth2
ip link set veth2 netns namespace2
brctl addbr br1
brctl addif br1 ens33
ifconfig ens33 0.0.0.0
ifconfig br1 192.168.90.43/22 up
brctl addif br1 veth1
ip netns exec namespace2 ifconfig veth2 192.168.90.47/22 up
ip netns exec namespace2 route add default gw 192.168.91.254
iptables -t filter -A FORWARD -m physdev --physdev-in ens33 --physdev-out veth1 -j ACCEPT
iptables -t filter -A FORWARD -m physdev --physdev-out ens33 --physdev-in veth1 -j ACCEPT


When I ping outside from my host, it works



ping 8.8.8.8


But when I ping from my namespace, it fails



ip netns exec namespace2 ping 8.8.8.8


I try to ping my gateway from 



ip netns exec namespace2 ping 192.168.91.254


It has about 70% package loss.



Why it that happen?






linux networking iptables




linux networking iptables






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Aug 17 at 8:29

























asked Aug 17 at 8:02









Don_Chen

1062




1062











  • Well I wrote an answer telling you forgot to bring veth1 up. But then I read about 70% packet loss (when it should have been 100%). So I'm at a loss and deleted the answer
    – A.B
    Aug 20 at 17:47










  • Eventually I found it's about arp for the ip - arp binding was wrong, but I don`t know why it would be wrong.
    – Don_Chen
    Aug 22 at 3:31
















  • Well I wrote an answer telling you forgot to bring veth1 up. But then I read about 70% packet loss (when it should have been 100%). So I'm at a loss and deleted the answer
    – A.B
    Aug 20 at 17:47










  • Eventually I found it's about arp for the ip - arp binding was wrong, but I don`t know why it would be wrong.
    – Don_Chen
    Aug 22 at 3:31















Well I wrote an answer telling you forgot to bring veth1 up. But then I read about 70% packet loss (when it should have been 100%). So I'm at a loss and deleted the answer
– A.B
Aug 20 at 17:47




Well I wrote an answer telling you forgot to bring veth1 up. But then I read about 70% packet loss (when it should have been 100%). So I'm at a loss and deleted the answer
– A.B
Aug 20 at 17:47












Eventually I found it's about arp for the ip - arp binding was wrong, but I don`t know why it would be wrong.
– Don_Chen
Aug 22 at 3:31




Eventually I found it's about arp for the ip - arp binding was wrong, but I don`t know why it would be wrong.
– Don_Chen
Aug 22 at 3:31















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