On average about 100 (TCP) requests hit my home router per minute doing various probing and scanning. Lots of checking for the telnet port obviously. Sometimes you can see a swarm of entirely different IPs scanning the full port range (probing the ports one-by-one).

You'll see a lot of deepfield, censys-scanner, visionheight.com, shadowserver.io, etc., but also the usual suspects of Chinese or Russian IPs.

With OpenWRT I use something like this: `tcpdump -i pppoe-wan 'inbound and tcp[tcpflags] & (tcp-syn|tcp-ack) == tcp-syn'`, or alternatively `tcpdump -i pppoe-wan 'inbound and tcp[tcpflags] & (tcp-syn|tcp-ack) == tcp-syn and not port 44000'`, if we have some torrent client running (e.g. here at port 44000) which would mess up the result. I'm not sure it's the best way to handle this, but it's definitely enlightening what bounces off on the router.

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miah_ an hour ago | parent | next [-]

The easiest way to deal with the usual suspects is to just block the entire countries network range(s). There really is no reason they should be connecting to your home router anyway, and you lose nothing from blocking them.

Sure their packets will still hit your router, but if they are dropped immediately at least you're not wasting a syn-ack on them.

	▲	tommyage 4 minutes ago \| parent [-]
		I, temporarly, banned some ip range. I didn't find a source for pinpointing countries; though I am interested. Could you point me to some sources which, deterministically, resolve to some countries? To my knowledge you can not reliably identify countries by ip since this would be dependent on DNS servers. Though I am just a application programmer! Thanks in advance.

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sroussey 20 minutes ago | parent | prev | next [-]

I have ubiquity UniFi for this reason (amongst others). OpenWRT is a good choice as well. Most home router software is such junk, might as well leave the door open..

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impish9208 an hour ago | parent | prev [-]

I can corroborate visionheight and shadowserver from my firewall logs.