[CentOS] ip6tables REJECT target 3s timeout

Banyan He banyan at rootong.com
Thu Nov 22 00:51:11 UTC 2012


how about telnet yourself via the lo interface? Is there something 
different then?

------------
Banyan He
Blog: http://www.rootong.com
Email: banyan at rootong.com

On 2012-11-22 12:40 AM, Markus Falb wrote:
> Hi,
> I am trying to get ipv6 firewall running. I did a very simple ip6tables
> rules and noticed very long running yum updates. I think that happened
> because firewall is dropping outgoing packets to port 80. Well, I
> thought to mitigate the issue and changed outgoing from drop to reject.
>
> Now I try manually
>
> # strace telnet 2a02:180:ffff:1::551f:b966 80
> ...
> connect(3, {sa_family=AF_INET6, sin6_port=htons(80), inet_pton(AF_INET6,
> "2a02:180:ffff:1::551f:b966", &sin6_addr), sin6_flowinfo=0,
> sin6_scope_id=0}, 28
>
> 3 second delay
>
> ) = -1 ECONNREFUSED (Connection refused)
> ...
>
> The ECONNREFUSED is quite expected of course, but what is not expected
> that the connect syscall lasts 3 seconds. This 3 second delay is not
> happening with a equivalent telnet to a IPv4 address.
>
> Why is this 3 second delay?



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