Thanks, I appreciate your comments. Zsombor
At 01:36 PM 6/23/2003 -0500, MADMAN wrote: >>>>> Were the two T1's terminating at two differant ISP's? If so BGP >>>>>would be appropriate. If you have 2 T1's terminating at a single ISP in >>>>>the same POP then no. >>>> >>>> >>>>What would you do if they had been terminating at a single ISP in the >>>>same POP? Or did you mean "same router"? >>> >>> >>> Most likely simple default routes. >> >>You mean default static routes? From a pure theoretical point of view, >>that seems a bit dangerous to me (to have two default static route >>pointing to two different routers). If one of the ISP routers is not >>directly connected to the customer's router (because for example there is >>an Ethernet switch in the middle), then the customer's router won't >>notice even if the ISP router is powered down. Even if the two routers >>are directly connected, it is possible (even though with current IOS >>versions it is not very likely) that the interface stays up even though >>routing dies on the ISP router. In short, I think there is a chance of >>you blackholing half of your traffic. >>Comments? :) >>Thanks, >>Zsombor > > Unless your co-located with your ISP your probably not connected to an > ethernet switch! Though even if serially connected, with static routes > you would not know if the LAN connection on the ISP router went down > effectively causing the same blackholing you refer to. > > Like most things there is a cost/benefit analysis. WAN links are more > prone to outages than the LAN, pointing your default to the ISP WAN is > simple and commonly used config. For cusomters that are more sensitive > to outages may opt for dual homing to 2 ISP's using ful routing and have > their WAN connections via a SHNS or SHARP configuration. > > Redundancy and simplicity are not bedfellows and the more your willing > to spend the more redundancy can be had. > > Dave > >> >>> Though as Howard alluded to there are some exceptions where you may >>> use BGP but not to recieve full routing but more likely to control >>> network announcements. You could exchange same router/POP as far as >>> routing is concerned. >>> >>> Dave > > >-- >David Madland >CCIE# 2016 >Sr. Network Engineer >Qwest Communications >612-664-3367 > >"Government can do something for the people only in proportion as it >can do something to the people." -- Thomas Jefferson Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=71201&t=70151 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
