TCP:RA/FA/FPA Flooding logs



  • …but I pretty sure there is no asymmetric routing happening.

    We have one physical (I use physical loosely as this is running in a vm on hyper-v) incoming connection on xxx.yyy.zzz.187. 1:1 natting is setup for .185/.186/.188 and .189.

    .187 is the default route for all traffic. Web servers etc hang off the other IP's and the nat'ing is controlled by the 1:1 entries.

    I'm seeing lots of TCP:RA/FA/FPA flooding the logs from ordinary client PC's but I don't understand why. Firewall rules allow only what we stipulate, everything else in and out is blocked.

    I am very new to pfSense so please be gentle with me, I have tried to diagnose this but to no avail.

    Best regards,

    Chris


  • Banned



  • Thanks doktonotor, I have had a look at these articles but I don't believe it is asymmetric routing. Why so many? 90 log entries in the 13 minutes since 16:00 GMT? Is that normal? On a network with client PC's only appearing the logs, of which 40 are in use at the moment, the rest are powered off…?



  • pf acts like it considers the connection to be torn down before it receives an ACK from the other end.  When that ACK arrives, it's now seen as an unsolicited inbound packet and blocked by the firewall.



  • I should say the blocked traffic is FROM the client PC (LAN) TO the external site (WAN).



  • Are you sure?



  • sorry, on the commute home.

    I think I'm reading it right… i.e.

    Nov 16 17:59:05 LAN 192.168.1.111:54254 132.245.226.50:443 TCP:RA



  • Definitely coming from LAN.  It's normal for a source to talk to a destination using a high ephemeral port (>1024).  No idea what's going on without more info, but I would not be alarmed.  Nothing nefarious seems to be happening.



  • I suppose it's being blocked so if it is nefarious t's doing no harm, but I would still like to understand. What "more info" can I get for you :-)



  • Since the traffic is coming from LAN, it shouldn't be blocked by anything unless you have added some blocking rules on LAN.  I'm positive its out-of-state packets.  Th eonly other thing to do, if you care, is to find out the application that is causing them.  Is the LAN device at .111 a WiFi unit?  They can be really funny when switching between WiFi and 4G, for example.



  • I block everything in and out, setting only rules to what I want. I have sat and watched (stared at) the logs for a week until I have caught (I think) everything out bound which is legitimate and ignored everything else i.e. port 843 Adobe policy server…not used so let it get blocked.

    I can account for just about everything apart from: -

    i) my DC/DNS/DHCP servers contacting unusual external servers on port 53. I only configure my DNS with 8.8.8.8, 8.8.4.4 as forwarders and allow traffic to same plus *.root-server.net and *.gtld-server.net, but I see (correctly) blocked traffic to 203.119.86.101:53, anysec.apnic.net (plus many others) for instance - still researching

    ii) This TCP/RA etc problem.

    .111 happens to be an iPhone so I can understand why this may happen but a lot of the other IP's are ordinary desktops.


  • Banned

    This out-of-state traffic is absolutely normal with smartphones. (They behave like retards when switching b/w cellular and wifi.)



  • Hmmm…I'll have to find a way of filtering it out otherwise it makes the logs as good as useless. I need to see out-of-the-ordinary stuff and don't fancy wading through reams of logs during my daily checks. Still doesn't explain why I get so many from ordinary desktops though...



  • @doktornotor:

    This out-of-state traffic is absolutely normal with smartphones. (They behave like retards when switching b/w cellular and wifi.)

    I second this. All of my android devices span the logs with this same crap. I disabled logging on my LAN because of it.



  • Still doesn't explain why I get so many from ordinary desktops though…

    If it's really bothering you, capture some traffic during these events and then look at the traces in Wireshark to see what's going on.



  • I've also been getting quite a few from the LAN side as well in my logs:

    block/1000000103	Nov 27 17:27:29	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.161:33200	23.21.79.72:443		TCP:RA
    block/1000000103	Nov 27 16:47:11	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.225:63814	103.245.222.133:80	TCP:RA
    block/1000000103	Nov 27 16:47:02	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.225:63814	103.245.222.133:80	TCP:FA
    block/1000000103	Nov 27 16:46:57	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.225:63814	103.245.222.133:80	TCP:FA
    block/1000000103	Nov 27 16:46:55	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.225:63814	103.245.222.133:80	TCP:FA
    block/1000000103	Nov 27 16:46:54	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.225:63814	103.245.222.133:80	TCP:FA
    block/1000000103	Nov 27 16:46:53	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.225:63814	103.245.222.133:80	TCP:FA
    block/1000000103	Nov 27 16:46:53	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.225:63814	103.245.222.133:80	TCP:FA
    block/1000000103	Nov 27 16:23:44	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52602		10.0.0.1:3128		TCP:RA
    block/1000000103	Nov 27 16:23:43	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52578		10.0.0.1:3128		TCP:RA
    block/1000000105	Nov 27 16:23:37	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34857	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 16:23:36	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34857	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000103	Nov 27 16:23:35	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52168		10.0.0.1:3128		TCP:RA
    block/1000000103	Nov 27 16:23:35	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52168		10.0.0.1:3128		TCP:FA
    block/1000000103	Nov 27 16:23:35	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52602		10.0.0.1:3128		TCP:FPA
    block/1000000103	Nov 27 16:23:34	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52168		10.0.0.1:3128		TCP:A
    block/1000000103	Nov 27 16:23:34	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52578		10.0.0.1:3128		TCP:FPA
    block/1000000103	Nov 27 16:23:33	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52168		10.0.0.1:3128		TCP:A
    block/1000000103	Nov 27 16:23:32	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52168		10.0.0.1:3128		TCP:A
    block/1000000103	Nov 27 16:23:31	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52168		10.0.0.1:3128		TCP:A
    block/1000000103	Nov 27 16:23:30	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52168		10.0.0.1:3128		TCP:A
    block/1000000103	Nov 27 16:23:30	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52168		10.0.0.1:3128		TCP:FA
    block/1000000103	Nov 27 16:23:30	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52602		10.0.0.1:3128		TCP:FPA
    block/1000000103	Nov 27 16:23:29	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52578		10.0.0.1:3128		TCP:FPA
    block/1000000103	Nov 27 16:23:29	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52168		10.0.0.1:3128		TCP:A
    block/1000000103	Nov 27 16:23:28	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52168		10.0.0.1:3128		TCP:A
    block/1000000103	Nov 27 16:23:27	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52168		10.0.0.1:3128		TCP:FA
    block/1000000103	Nov 27 16:23:27	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52602		10.0.0.1:3128		TCP:FPA
    block/1000000103	Nov 27 16:23:27	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52168		10.0.0.1:3128		TCP:A
    block/1000000103	Nov 27 16:23:27	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.21:52578		10.0.0.1:3128		TCP:FPA
    block/1000000105	Nov 27 16:19:50	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34828	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 16:19:35	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34828	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 16:19:26	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34828	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 16:19:22	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34828	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 16:19:20	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34828	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 16:19:19	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34828	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 16:18:50	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34807	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 16:18:34	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34807	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 16:18:25	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34807	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 16:18:21	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34807	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 16:18:19	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34807	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 16:18:18	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34807	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 15:19:28	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34477	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 15:19:24	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34477	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 15:19:22	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34477	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 15:19:21	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34477	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 15:18:51	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34453	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 15:18:35	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34453	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 15:18:27	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34453	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 15:18:23	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34453	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 15:18:21	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34453	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000105	Nov 27 15:18:20	LAN 	Default deny rule IPv6 (1000000105)	[fe80::dddd:bbbb:3333:4444]:34453	[fd30:eeee:6666:9999::1]:3128	TCP:S
    block/1000000103	Nov 27 13:51:28	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.161:33114	23.21.79.72:443		TCP:RA
    block/1000000103	Nov 27 11:57:25	LAN 	Default deny rule IPv4 (1000000103)	10.0.0.161:33055	23.21.79.72:443		TCP:RA
    

    A lot of the traffic appears to be coming from a Windows 8 laptop (10.0.0.21 & fe80::dddd:bbbb:3333:4444) to the squid3 proxy on my pfSense firewall.

    Other traffic is from my Sonos system (10.0.0.161) and a Windows Server 2012 R2 VM (10.0.0.225) both of which a set to bypass the proxy.

    I have the following firewall rules on the LAN interface which should allow this traffic:

    IPv4 * 	LAN net 	* 	* 	* 	* 	none 	  	Default allow IPv4 LAN to any rule  	
    IPv6 * 	LAN net 	* 	* 	* 	* 	none 	  	Default allow LAN IPv6 to any rule  
    

  • LAYER 8 Global Moderator

    And what part do you not understand about OUT OF STATE traffic?

    If you don't want to see it then turn off logging of default rule, create your own block rule that logs but only if SYN if no SYN then doesn't block or log but will fall through to the default and get blocked but not logged.


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