Flap protection kick in with BGP session going up and down... Withdrawing routes via filters does not ...
:) 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: "George Skorup" <[email protected]> > To: [email protected] > Sent: Friday, September 9, 2016 1:47:59 PM > Subject: Re: [AFMUG] Bgp automatic drop session? > Just be careful with withdraws and re-announcements frequently. You may > trigger > your upstream's flap protection, damping, etc. Every carrier we peer with does > it. AT&T is the most aggressive at policing advertisements based on my past > experience a couple years ago, and I highly doubt they've toned it down any. > Had a power issue at a site and our router rebooted a couple times in 5 > minutes. They wouldn't take our advertisement anymore. Took seven freakin > hours > to get an engineer to clear it. So, try not to shoot yourself in the foot. > On 9/9/2016 9:12 AM, Faisal Imtiaz wrote: >> 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??
