Yeah, DHCP lease info is the thing to save. From: Adam Moffett Sent: Wednesday, December 28, 2016 9:21 AM To: [email protected] Subject: Re: [AFMUG] Mikrotik - Carrier Grade NAT methods
I think Eric is saying if you're going to the effort of logging NAT translations then you also should log DHCP assignments. Which is true. ------ Original Message ------ From: "Dennis Burgess" <[email protected]> To: "[email protected]" <[email protected]> Sent: 12/28/2016 5:50:22 AM Subject: Re: [AFMUG] Mikrotik - Carrier Grade NAT methods But this is not required.. Something of course, you can do. Dennis Burgess www.linktechs.net – 314-735-0270 x103 – [email protected] From: Af [mailto:[email protected]] On Behalf Of Eric Kuhnke Sent: Tuesday, December 27, 2016 8:01 PM To: [email protected] Subject: Re: [AFMUG] Mikrotik - Carrier Grade NAT methods Assuming you have a NAT and dhcp pools of IPs defined inside the NAT, unique pool per POP, if you do not have log files from your dhcp daemon, you are taking a terrible risk... Log files are small relative to the cost of disk space. In setups I have built in the past with the ISC dhcpd we kept logs going back 24 months for which CPE at which MAC address had which IP address (whether internal or an ARIN IP) at any given point in time, including the lease/assignment handshake. On Tue, Dec 27, 2016 at 5:58 PM, Mathew Howard <[email protected]> wrote: The problem I see with that though, is the subpoenas we've gotten are generally just an IP address, and a time period... if this is coming from something like, say, a facebook post, is there typically going to be any log of that sort of thing? Assigning port blocks would work fine for things like bittorrent DMCA takedown notices, where they give you port information, but I'm not sure how you would use it to track down a specific customer when all they give you is the IP address... On Tue, Dec 27, 2016 at 6:51 PM, Josh Reynolds <[email protected]> wrote: If you assign a port block per customer (PBA NAT in Juniper), you don't really need to log anything... do you? On Tue, Dec 27, 2016 at 3:45 PM, Adam Moffett <[email protected]> wrote: > A recent thread about a subpoena made me wonder. Historically this hasn't > been an issue for me because I've had access to enough public IP's...but it > might become an issue soon. > > Has anybody set up CGN with appropriate logging on Mikrotik? > I'm thinking you would have to log every set of src-ip, dst-ip, src-port, > and dst-port for each connection that a customer opens. Does simply > checking the "log" checkbox on the srcnat rule generate enough data or is > there more to it? > > Has anybody tried the method on the wiki > (http://wiki.mikrotik.com/wiki/Manual:IP/Firewall/NAT#Carrier-Grade_NAT_.28CGNAT.29_or_NAT444) > where you assign a range of port numbers to each private IP? The idea is > you don't have to log everything at that point because you know that a > connection from port x corresponds to private ip y. Then you just need to > keep track of who has which private IP. It seems like this would have a > side effect of limiting the number of simultaneous connections a single > customer could open....maybe not a bad thing. > > Thanks, > Adam
