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Thread Index [isp-bgp] Re: Routing Information
There is always a catch :) How would I properly account for redundancy if I'm using HSRP? 2 routers, 2 providers connected to an internal switch and connected to each other via crossover. If a router looses conductivity to the switch along with the other router at the same time and still advertises it's routes there is a blackhole of sorts. Am I just overanalyzing the problem? I realize the chance of 2 Ethernet links going down at the same time while the Serial interface of the router is still working is very far fetched. Is it even reasonable to account for such an occurrence? Serge. ----- Original Message ----- From: "James" <haesu@...> To: <isp-bgp@isp-bgp.com> Sent: Sunday, February 29, 2004 12:58 AM Subject: [isp-bgp] Re: Routing Information yes you are missing something.. :P if the router doesnt see the route and drops the bgp advertisement.. that's all fine and dandy... but... now what happens if your ethernet starts flapping hard? you are going to start flapping bgp advertisements. now that might not be a problem for you if this is bgp over an internal network that does not propagate the advertisements to the internet.. but if this is a live bgp session with your upstream isp and what not, you are going to experience some serious dampening penalties after enough flaps. flapping leads to dampening. dampening leads to suffering. besides... if the route becomes unavailable, it can be safely routed to bitbucket anyway. my 0.02 -J -- James Jun (formerly Haesu) TowardEX Technologies, Inc. 1740 Massachusetts Ave. Boxborough, MA 01719 Consulting, IPv4 & IPv6 colocation, web hosting, network design & implementation http://www.towardex.com | james@towardex.com Cell: (978)394-2867 | Office: (978)263-3399 Ext. 170 Fax: (978)263-0033 | AIM: GigabitEthernet0 NOC: http://www.twdx.net | POC: HAESU-ARIN, HDJ1-6BONE On Sun, Feb 29, 2004 at 12:54:08AM -0500, Serge Paquin wrote: > Thanks for the quick reply. > > Actually I'm thinking about not having the floating route. If the router > cannot see the internal switch and it's local neighbor router it has nowhere > to send the traffic so I figure it should not be advertising. > > I see everyone always recommending a floating route but I figure that could > give me a type of local blackhole. > > Am I missing something? > > Serge. > > ----- Original Message ----- > From: "James" <haesu@...> > To: <isp-bgp@isp-bgp.com> > Sent: Sunday, February 29, 2004 12:49 AM > Subject: [isp-bgp] Re: Routing Information > > > > If there is no static route to a locally BGP advertised block BGP will > > not advertise? > > correct. > > thats why you can either a) advertise a connected route or > b) set a floating static route. > > > ie: > > route1 advertises 192.168.0.0/24 via BGP > > i.e. do this: > > conf t > router bgp blah > network 192.168.0.0 mask 255.255.255.0 > exit > ip route 192.168.0.0 255.255.255.0 192.168.1.1 > ip route 192.168.0.0 255.255.255.0 192.168.2.1 50 > ! The floating route to null. > ip route 192.168.0.0 255.255.255.0 Null0 254 > > can also use 'permanent' as well. > > -J > > -- > James Jun (formerly Haesu) > TowardEX Technologies, Inc. > 1740 Massachusetts Ave. > Boxborough, MA 01719 > Consulting, IPv4 & IPv6 colocation, web hosting, network design & > implementation > http://www.towardex.com | james@towardex.com > Cell: (978)394-2867 > Fax: (978)263-0033 | AIM: GigabitEthernet0 > NOC: http://www.twdx.net | POC: HAESU-ARIN, HDJ1-6BONE > > > > > static route: > > ip route 192.168.0.0 255.255.255.0 192.168.1.1 > > ip route 192.168.0.0 255.255.255.0 192.168.2.1 50 > > > > If the router looses it's like to the 192.168.1.0 and 192.168.2.0 > > networks the static routes become invalid and theirfore the router will > stop > > advertising 192.168.0.0/24 via BGP? > > > > Thanks, > > Serge. > > > > > > > > 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. > > > > ------------------------ANNOUNCEMENT--------------------------------- > > --------------------------------------------------------------------- > > - ISPCON Spring 2004 - Washington DC Hilton & Towers - > > > > - The ISP and WISP event - www.ispcon.com - > > > > - Informative. Substantive. Instructive - > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > > > 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. > > ------------------------ANNOUNCEMENT--------------------------------- > --------------------------------------------------------------------- > - ISPCON Spring 2004 - Washington DC Hilton & Towers - > > - The ISP and WISP event - www.ispcon.com - > > - Informative. Substantive. Instructive - > ---------------------------------------------------------------------- > ---------------------------------------------------------------------- > > > > > 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. > > ------------------------ANNOUNCEMENT--------------------------------- > --------------------------------------------------------------------- > - ISPCON Spring 2004 - Washington DC Hilton & Towers - > > - The ISP and WISP event - www.ispcon.com - > > - Informative. Substantive. Instructive - > ---------------------------------------------------------------------- > ---------------------------------------------------------------------- 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. ------------------------ANNOUNCEMENT--------------------------------- --------------------------------------------------------------------- - ISPCON Spring 2004 - Washington DC Hilton & Towers - - The ISP and WISP event - www.ispcon.com - - Informative. Substantive. Instructive - ---------------------------------------------------------------------- ---------------------------------------------------------------------- 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. ------------------------ANNOUNCEMENT--------------------------------- --------------------------------------------------------------------- - ISPCON Spring 2004 - Washington DC Hilton & Towers - - The ISP and WISP event - www.ispcon.com - - Informative. Substantive. Instructive - ---------------------------------------------------------------------- ----------------------------------------------------------------------
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