|
Thread Index RE: [isp-bgp] BGP announcement question
I intend to get another AS, the question was specifically towards announcing the larger /20 from Site A and the smaller /23 from Site B. Since this is possible, I will likely do this, or possibly break my /20 into a /21 and several smaller subnets, since I typically use and allocate them as /24s or /23s anyways. ------------------------------------ SmartTel Communications Jim Barstow Sr. Telecom Engineer jimb@smarttelco.com PO Box 367 22645 Canal Road Suite E Orange Beach, AL 36561 tel: (251) 224-0868 fax: (251) 224-0830 mobile: (251) 747-4913 ------------------------------------ -----Original Message----- From: Marshall Eubanks [mailto:tme@multicasttech.com] Sent: Wednesday, February 28, 2007 2:03 PM To: isp-bgp@isp-bgp.com Subject: Re: [isp-bgp] BGP announcement question I would just pay the money and get a second AS. Regards Marshall On Feb 28, 2007, at 2:50 PM, James Jun wrote: > Well one thing you need to be worried about is communication between > Sites A and B. If you are using same AS number, BGP's loop detection > will reject hearing of Site B's prefixes/route announcements at Site A > and vice versa. > (Though if you take last resort default route from your upstreams, > that is not exactly a problem with exception of lack of sufficient > NLRI information for diverse route selection) > > You can overcome this by using 'allowas-in' on your transit neighbor > sessions to your uplink ISPs, but such hack should always be temporary > and be well documented as it can also create other event-specific > problems for networks with changing topology in the future. Another > option available to overcome this without using that hack is to apply > for another AS number from ARIN. ARIN policies do allow acquisition > of more AS numbers if you have different sites multihomed while > maintaining their own routing policy (in other words, disconnected > island POP's multihomed to separate ISPs at each location, not > connected by a transport). > > Lastly, you can also buy transport (which is costly or moderately ok > depending on locations involved) or setup a GRE tunnel if inter- site > traffic is minimal or manageable to handle through tunnel link. In > such case, ensuring that your transit links can handle more than 1500 > bytes of MTU would help, as 1476 MTU based GRE tunnels are royal pain. > > Regards, > james > > > -----Original Message----- > From: Jim Barstow [mailto:jimb-clec@dssitech.com] > Sent: Wednesday, February 28, 2007 2:41 PM > To: isp-bgp@isp-bgp.com > Subject: RE: [isp-bgp] BGP announcement question > > I am aware of this.. Site B is to be multihomed to help prevent this, > as currently a link from Site A to Site B is not yet feasible. > > > ------------------------------------ > SmartTel Communications > Jim Barstow > Sr. Telecom Engineer > jimb@smarttelco.com > PO Box 367 > 22645 Canal Road > Suite E > Orange Beach, AL 36561 > tel: (251) 224-0868 > fax: (251) 224-0830 > mobile: (251) 747-4913 > ------------------------------------ > > > > mailto:remove-isp-bgp@isp-bgp.com > To unsubscribe via postal mail, please contact us at: > Jupitermedia Corp. > Attn: Discussion List Management > 475 Park Avenue South > New York, NY 10016 > > Please include the email address which you have been contacted with. > > Copyright 2005 Jupitermedia Corporation All Rights Reserved. mailto:remove-isp-bgp@isp-bgp.com To unsubscribe via postal mail, please contact us at: Jupitermedia Corp. Attn: Discussion List Management 475 Park Avenue South New York, NY 10016 Please include the email address which you have been contacted with. Copyright 2005 Jupitermedia Corporation All Rights Reserved. To unsubscribe via postal mail, please contact us at: Jupitermedia Corp. Attn: Discussion List Management 475 Park Avenue South New York, NY 10016 Please include the email address which you have been contacted with. Copyright 2005 Jupitermedia Corporation All Rights Reserved.
Thread Index |
|
