Softethervpn: Duplicate packets on RAW IP Mode

[andr-04]

Introduced in build 9582 RAW IP Mode causing duplicate packets on ping an external IP where SoftEther installed on.

# ping vps.*
PING vps.* (86.*.*.*) 56(84) bytes of data.
64 bytes from vps (86.*.*.*): icmp_seq=1 ttl=64 time=0.112 ms
64 bytes from vps (86.*.*.*): icmp_seq=1 ttl=128 time=0.353 ms (DUP!)
64 bytes from vps (86.*.*.*): icmp_seq=2 ttl=64 time=0.096 ms
64 bytes from vps (86.*.*.*): icmp_seq=2 ttl=128 time=0.328 ms (DUP!)
64 bytes from vps (86.*.*.*): icmp_seq=3 ttl=64 time=0.064 ms
64 bytes from vps (86.*.*.*): icmp_seq=3 ttl=128 time=0.228 ms (DUP!)

[djh00t]

I have noticed this issue as well.

[ruijzhan]

You can drop the second ping response by:
iptables -A OUTPUT -p icmp -m ttl --ttl-gt 100 -j DROP

[Nemesiz]

Older SoftEther did not had this issue. After commit (4e862a7e40c095ac6ac8b1417890008fbd614ebb v4.19-9582-beta) it started. I noticed then SofEther virtual NAT is on iptables creates rules:

-A OUTPUT ! -s 127.100.47.233/32 ! -d 127.125.132.32/32 -p icmp -m icmp --icmp-type 3/3 -m connmark ! --mark 0x7d6a5169 -j DROP
-A OUTPUT ! -s 127.95.78.210/32 ! -d 127.154.73.57/32 -p tcp -m tcp --sport 61001:65535 --tcp-flags RST RST -m connmark ! --mark 0x51907ff3 -j DROP

[davidebeatrici]

245

[szabolcsf]

can confirm this still persist with version 4.29-6980-rtm
setting bool DisableIpRawModeSecureNAT true stop the DUP! responses

[oscx]

is duplicate ping response a bug or expected behaviour - with SecureNAT enabled mode?

[emptyway]

had to use this setting bool DisableIpRawModeSecureNAT true too

[mrez-ir]

I also was searching for similar problem to find out why I can not disable icmp ping requests on my server. In my case I have disabled ping requests for my CentOS server using "net.ipv4.icmp_echo_ignore_all = 1" at sysctl and logically my server IP should not answer any ping requests. But still getting ping feedbacks until I changed online state of softethers VPN to offline! I find out SoftEthers VirtualHUB is automatically answering ping requests on its own regardless of OS configuration. (version 4.29 build 9680)

[mrez-ir]

is duplicate ping response a bug or expected behaviour - with SecureNAT enabled mode?

Please somebody answer this question. I doubt it would be expected.

[chipitsine]

@mrez-ir , version 4.29 build 9680 is SE VPN Stable edition.
you are asking question in SE VPN Developer edition issue tracker.

it is wrong tracker for asking Stable edition questions. Can you try to reproduce your issue in Developer edition ?

[mrez-ir]

@chipitsine No I was using SE VPN for my own use and prefer to use most stable versions and yes this problem happens to be started/exist on this stable edition.

[chipitsine]

But you are asking in wrong issue tracker. It is related to developer edition, not stable

[mrez-ir]

@chipitsine OK sorry for that. I just redirected from google. Saw the same bug report.

[chipitsine]

@mrez-ir , you are welcome to join development

[mrez-ir]

@chipitsine OK, I'll be happy to help.

[danielaskdd]

I have same problem. Why this issue still in no one assigned status for 3 years?

[paulmenzel]

I have same problem. Why this issue still in no one assigned status for 3 years?

Do you have a support contract? If not, where do you get the expectation from that something should be worked on?

[temskiy]

Version 4.19 Build 9578 have no this problem. Temporary workaround - use old verion :(

[chipitsine]

I have same problem. Why this issue still in no one assigned status for 3 years?

it is open source project with no road map. if you or anyone else volunteer to resolve an issue, no problem