I'm running ubuntu 14.04 as a gateway, routing is controlled by iptables.

I'm getting a number of strange blocks in UFW which seem to effect established connections. Is there any way this block would effect established connections or a website loading/video streaming?

Jan 12 21:15:39 ukxn kernel: [126249.931956] [UFW BLOCKaa] IN=eth0
OUT= MAC=04:01:88:e6:06:01:84:b5:9c:f9:f8:30:08:00 SRC=
DST= LEN=88 TOS=0x00 PREC=0x00 TTL=86 ID=53926 DF PROTO=TCP
SPT=443 DPT=51722 WINDOW=16080 RES=0x00 ACK URGP=0


  • We need the context of your overall iptables rule set to be able to answer (and maybe not even then). Please edit your question adding the outputs of sudo iptables -v -x -n -L and sudo iptables -t nat -v -x -n -L. However, be aware that some (like me) are not fond of looking at UFW generated iptables rule sets. – Doug Smythies Jan 13 '16 at 19:50

To answer your question, yes.

What that log message is telling me is that packets from source (or https://facebook.com) are being blocked, likely in your FORWARD chain if the connection is originating from your LAN and not your Ubuntu gateway. If the connection is originating from your Ubuntu gateway, the block will likely be in your INPUT chain.

I concur with Doug Smythies. Please edit your post to contain the output of the command iptables -vnL in order for us to better understand your scenario.

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