I have 4 tap interfaces, tap0 and tap1 is connected and so is tap2 and tap3
vde_switch -d -tap tap0 -tap tap1 click vde_switch -d -tap tap2 -tap tap3 --sock /run/vde.ctl/ctl2 I then assigned ip for tap1 and tap2
ip addr add 1.1.1.1/24 dev tap1 ip addr add 1.2.1.1/24 dev tap2 From raw socket application, I sent a udp packet from tap0 with source ip 1.1.1.3 and destination ip 1.2.1.3 and it arrived at tap3 (according to wireshark).
The problem is, if I send fragmented ip/udp packet, Linux doesn't forward it to tap3.
I checked the fragmented ip packet (first segment), its checksum and destination mac addr are all right. The funny thing is, if I remove the "more fragment" bit in ip header (ip checksum will change), then it got forwarded.
By the way, I am using Linux 3.19.0-65 on 64bit laptop.
Any idea why? Thanks a lot!
EDIT1
Here is the output of ip route list
default via 10.0.0.1 dev wlan0 proto static 1.1.1.0/24 dev tap1 proto kernel scope link src 1.1.1.1 1.2.1.0/24 dev tap2 proto kernel scope link src 1.2.1.1 10.0.0.0/24 dev wlan0 proto kernel scope link src 10.0.0.3 metric 9 172.16.83.0/24 dev vmnet1 proto kernel scope link src 172.16.83.1 172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1 192.168.181.0/24 dev vmnet8 proto kernel scope link src 192.168.181.1 Edit2
Here is the link to the pcap of the IP fragment packet, captured on tap0 interface.
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