simple.... Adding routes and removing routes is a defined bgp function, and it is considered to be one of a softer impact...
killing a bgp session is disruptive, unexpected, depending on timeouts, it can take as long a 3min to determine if the peer is gone, and then another few min for the routes to fully propagate across the internet.. meanwhile traffic is still heading your way... Regards Faisal Imtiaz Snappy Internet & Telecom 7266 SW 48 Street Miami, FL 33155 Tel: 305 663 5518 x 232 Help-desk: (305)663-5518 Option 2 or Email: [email protected] > From: "Josh Luthman" <[email protected]> > To: [email protected] > Sent: Friday, September 9, 2016 10:01:24 AM > Subject: Re: [AFMUG] Bgp automatic drop session? > Oh well that's easy enough. Why is that better than disabling the peer? > Josh Luthman > Office: 937-552-2340 > Direct: 937-552-2343 > 1100 Wayne St > Suite 1337 > Troy, OH 45373 > On Fri, Sep 9, 2016 at 9:58 AM, Faisal Imtiaz < [email protected] > > wrote: >> This goes back to best practices... >> you should be using a filter to advertise the routes... >> e.g. our hiq-out filter ..... >> 0 chain=hiq-out match-chain=SDF-11280 invert-match=no action=accept >> set-bgp-prepend=2 set-bgp-prepend-path="" >> 1 X chain=hiq-out match-chain=SDG-10302 bgp-communities=11280:115 >> invert-match=no action=accept set-bgp-prepend=3 set-bgp-prepend-path="" >> 2 chain=hiq-out match-chain=TNN-46215 bgp-communities=11280:115 >> invert-match=no >> action=accept set-bgp-prepend-path="" >> 3 chain=hiq-out bgp-communities=11280:245 invert-match=no action=accept >> set-bgp-prepend-path="" >> 4 X chain=hiq-out bgp-communities=11280:135 invert-match=no action=accept >> set-bgp-prepend-path="" >> 5 chain=hiq-out bgp-communities=11280:666 invert-match=no action=accept >> set-bgp-prepend-path="" >> 6 X chain=hiq-out bgp-as-path=^29846_* bgp-communities=11280:235 >> invert-match=no >> action=accept set-bgp-prepend-path="" >> 7 chain=hiq-out invert-match=no action=discard set-bgp-prepend-path="" >> As you can see a couple of chain's are disabled (X)..... that will withdraw >> the >> prefixes as defined in referenced chains. >> Regards. >> Faisal Imtiaz >> Snappy Internet & Telecom >> 7266 SW 48 Street >> Miami, FL 33155 >> Tel: 305 663 5518 x 232 >> Help-desk: (305)663-5518 Option 2 or Email: [email protected] >>> From: "Josh Luthman" < [email protected] > >>> To: [email protected] >>> Sent: Friday, September 9, 2016 9:50:20 AM >>> Subject: Re: [AFMUG] Bgp automatic drop session? >>> How would you "withdraw routes" on a Mikrotik? >>> Josh Luthman >>> Office: 937-552-2340 >>> Direct: 937-552-2343 >>> 1100 Wayne St >>> Suite 1337 >>> Troy, OH 45373 >>> On Fri, Sep 9, 2016 at 9:47 AM, Faisal Imtiaz < [email protected] > >>> wrote: >>>> Tut tut Tut ...... >>>> let's not start with bad habits... >>>> Best practices would be to withdraw the routes, and not kill the bgp >>>> session... >>>> :) >>>> Faisal Imtiaz >>>> Snappy Internet & Telecom >>>> 7266 SW 48 Street >>>> Miami, FL 33155 >>>> Tel: 305 663 5518 x 232 >>>> Help-desk: (305)663-5518 Option 2 or Email: [email protected] >>>>> From: "TJ Trout" < [email protected] > >>>>> To: [email protected] >>>>> Sent: Friday, September 9, 2016 1:31:10 AM >>>>> Subject: [AFMUG] Bgp automatic drop session? >>>>> Does anyone run any type of script that will automatically drop a bgp >>>>> session >>>>> when a upstream is having problems but isn't hard down ? Like packet >>>>> loss, high >>>>> latency or low throughout? >>>>> I'm assuming it's nearly impossible without human intervention??
