Re: bgp error problem

ullasmoopz · ‎02-14-2011

Hi all

When I configure bgp ,i am getting error

The below is the configuration. ??

interface GigabitEthernet0/0
ip address dhcp
duplex half
speed auto
!
interface GigabitEthernet0/1
ip address 10.1.0.2 255.255.255.252
duplex auto
speed auto

!

router bgp 64696

neighbor 10.1.0.1 remote-as 64696

----------------------------------------------------------------------------------------------

This is the error message

*Feb 14 11:23:19.095: %BGP-3-NOTIFICATION: sent to neighbor 10.1.0.1 passive 2/2
(peer in wrong AS) 2 bytes FC05
*Feb 14 11:23:19.095: %BGP-4-MSGDUMP: unsupported or mal-formatted message recei
ved from 10.1.0.1:
FFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFF 002D 0104 FC05 005A C2AA 871A 1002 0E01

0400 0100 0102 0041 0400 00FC 05
*Feb 14 11:23:25.195: %BGP-3-NOTIFICATION: sent to neighbor 10.1.0.1 active 2/2
(peer in wrong AS) 2 bytes FC05
*Feb 14 11:23:25.195: %BGP-4-MSGDUMP: unsupported or mal-formatted message recei
ved from 10.1.0.1:
FFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFF 002D 0104 FC05 005A C2AA 871A 1002 0E01

0400 0100 0102 0041 0400 00FC 05
*Feb 14 11:23:25.219: %BGP_SESSION-5-ADJCHANGE: neighbor 10.1.0.1 IPv4 Unicast t
opology base removed from session BGP Notification sent
*Feb 14 11:23:25.223: %BGP-3-NOTIFICATION: sent to neighbor 10.1.0.1 passive 2/2
(peer in wrong AS) 2 bytes FC05
*Feb 14 11:23:25.223: %BGP-4-MSGDUMP: unsupported or mal-formatted message recei
ved from 10.1.0.1:
FFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFF 002D 0104 FC05 005A C2AA 871A 1002 0E01

0400 0100 0102 0041 0400 00FC 05
-------------------------------------------------------

router#sh bgp nei
BGP neighbor is 10.1.0.1, remote AS 64696, internal link
BGP version 4, remote router ID 194.X.X.X
BGP state = Idle
Neighbor sessions:
0 active, is multisession capable
Default minimum time between advertisement runs is 0 seconds

For address family: IPv4 Unicast
BGP table version 1, neighbor version 1/0
Output queue size : 0
Index 0
                                 Sent       Rcvd
Prefix activity:               ----       ----
    Prefixes Current:               0          0
    Prefixes Total:                 0          0
    Implicit Withdraw:              0          0
    Explicit Withdraw:              0          0
    Used as bestpath:             n/a          0
    Used as multipath:            n/a          0
-----------------------------------------------------------------------------

Pls help

thanks & regards

Ullas

cadet alain · ‎02-14-2011

Hi,

The other side is in AS 64517( 0xFC05).

Regards.

Alain.

Don't forget to rate helpful posts.

ullasmoopz · ‎02-14-2011

Hi Alain,

Thank you,

Working fine now.

regards

Ullas

jain.manish94 · ‎07-12-2017

Hello please can you tell me how did you convert

The other side is in AS 64517( 0xFC05). ?

i am getting same error.

2 bytes FDE6 what does this means and how to convert it. please help me.

Hector Gustavo Serrano Gutierrez · ‎07-13-2017

Just convert from Hex to Decimals with a calculator.

Hex	Decimal
0xFDE6	64998

HTH.

Regards.

jain.manish94 · ‎07-13-2017

i thing this is not a right way to give the ans during interview.

Hector Gustavo Serrano Gutierrez · ‎07-13-2017

Hi jain.manish94,

Could you please elaborate in your request? I don't understand what you are looking for.

Do you need to know how come 0xFDE6 gives you 64998? It is just math, Hex to Decimal conversion.

I am more than glad to give you an answer based on your question.

Please let me know if I can be of help.

jain.manish94 · ‎07-13-2017

suppose i am attending interview and get this error .

%BGP-3-NOTIFICATION: sent to neighbor 172.31.1.3 2/2 (peer in wrong AS) 2 bytes FDE6 FFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFF 002D 0104 FDE6 00B4 ...

How to know that what is the AS no. another site. I know that i can convert this value and come to know the AS no.

for example here is FDE6

here i don have any calculator during interview and i want to describe there.

Hector Gustavo Serrano Gutierrez · ‎07-13-2017

Hi jain.manish94,

Now that you have formulated your question correctly, I can take the right approach to give you an answer.

It is interesting because it is simple math hexadecimal/binary/decimal conversion and not Cisco specific. But here is the general process.

As far as I know you must do the math calculation which can be convoluted, no shortcut to get the answer.

First of all, you need to know how Hex to Binary conversion works and a little bit of math.

Step 1) From the Hexadecimal value, convert it to binary in chunks of 4 bits. You can use the below table for reference.

Hex	Binary
0	0000
1	0001
2	0010
3	0011
4	0100
5	0101
6	0110
7	0111
8	1000
9	1001
A	1010
B	1011
C	1100
D	1101
E	1110
F	1111

You can either memorize this table or understand that each binary bit represents a power of 2 increasing with each bit from right to left.

Doing Hex to Binary conversion for each 4 bits, gives you:

FDE6

F	1111
D	1101
E	1110
6	0110

Resulting in:

FDE6 = 1111 1101 1110 0110

Step 2)

Here is when the interesting part comes, as you need to manually convert this whole Binary value to Decimal.

Here just the first portion so you can get the idea.

1111 1101 1110 0110

 Math:   2^9 + 2^8 + 2^7 + 2^6 + 2^5 + 2^4 + 2^3 + 2^2 + 2^1 + 2^0
Decimal:  0     1  |  1     1     1     0  |  0     1     1     0
        ===========================================================
Partial   0  + 256 + 128 + 64  + 32  +  0  +  0  +  4  +  2  +  0  
Results:
    
Once you complete this process (just part of it here) sum all the partial results. The final result will be 64998

There are plenty of web resources that can help you to reinforce this information if necessary.

HTH

jain.manish94 · ‎07-13-2017

i did not get this

1111 1101 1110 0110

 Math:   2^9 + 2^8 + 2^7 + 2^6 + 2^5 + 2^4 + 2^3 + 2^2 + 2^1 + 2^0
Decimal:  0     1  |  1     1     1     0  |  0     1     1     0
        ===========================================================
Partial   0  + 256 + 128 + 64  + 32  +  0  +  0  +  4  +  2  +  0  
Results:

Please can you describe more.