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BGP Backdoor 

JULY 22, 2012 LEAVE A COMMENT

 

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BGP backdoor command !en "#ed a# an o$t%on at t!e end o& t!e netork command #et# t!e netork #$ec%&%ed to

an A' o& 200 %n#tead o& 20( T!%# a))o# &or an *GP ro"te to take $recedence o& o+er t!e rece%+ed EBGP ro"te(

*& t!e )%nk beteen 2 and - .a0/0 oe# don Loo$back netork o& t!e#e to ro"ter# %)) )o#e connect%+%t e+en

t!o"! t!ere %# a red"nd"nt )%nk beteen t!e#e to ro"ter#( T!e #o)"t%on %# to ad+ert%#e t!e#e Loo$back# %nto BGP

b"t t!en t!e tra&&%c beteen netork# 10(1(2(0/23 and 10(1(-(0/23 %)) #tart tak%n& #"b4o$t%ma) $at! +%a 1 and not

"#%n d%rect $at! beteen 2 and - ca"#e o& t!e A' d%&&erene 5EBGP620 , E*GP 6 708 T!ere are &e a# to &%9 %t

and one o& t!em %# BGP Backdoor 

To Configure

R2(config)#router bgp 100

R6(config-router)#net 150.1.3.0 mask 255.255.255.0 backdoor

T!%# #et# t!e A' &or t!e ro"te 10(1(-(0/23 to an A' o& 200 a))o%n t!e *GP ro"te to be more $re&erred

7/17/2019 BGP Backdoor

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 Anot!er #o)"t%on to t!%# o")d be to #et t!e ne9t !o$ o& t!e rece%+ed BGP ro"te to t!e $at! de#%red !oe+er t!%# doe#

take aa red"ndanc #!o")d t!e ne9t !o$ &a%)