Cálculo com endereço IP no Excel - parte 3

Para separar a rede 10.11.12.34/17 (por ex.) em rede e mascara (ou wildcard), use as seguintes fórmulas:

Considerando a informação da rede/máscara na célula A1, segue a fórmula para a conversão da máscara:

=HEX2DEC(MID(DEC2HEX(2^32-(2^(32-A1));8);1;2)) &"."&
HEX2DEC(MID(DEC2HEX(2^32-(2^(32-A1));8);3;2)) &"."&
HEX2DEC(MID(DEC2HEX(2^32-(2^(32-A1));8);5;2)) &"."&
HEX2DEC(MID(DEC2HEX(2^32-(2^(32-A1));8);7;2))

Resultando em 255.255.128.0. Para converter em wildcard:

=HEX2DEC(RIGHT(DEC2HEX(-HEX2DEC(MID(DEC2HEX(2^32-(2^(32-Masks));8);1;2))-1);2)) &"."&
HEX2DEC(RIGHT(DEC2HEX(-HEX2DEC(MID(DEC2HEX(2^32-(2^(32-Masks));8);3;2))-1);2)) &"."&
HEX2DEC(RIGHT(DEC2HEX(-HEX2DEC(MID(DEC2HEX(2^32-(2^(32-Masks));8);5;2))-1);2)) &"."&
HEX2DEC(RIGHT(DEC2HEX(-HEX2DEC(MID(DEC2HEX(2^32-(2^(32-Masks));8);7;2))-1);2))

Resultado: 0.0.127.255

 

Cisco - Filtro de community (BGP)

Para filtrar uma community no BGP:

ip community-list 1 permit 65000:1234
!
route-map filter_community deny 10
 match community 1
!
route-map filter_community permit 20
!
router bgp 65000
 neighbor 10.10.10.2 route-map filter_community in
!

 

Cisco: domain-lookup

Para disabilitar o domain-lookup apenas para a sessão atual, use

terminal no domain-lookup

 

Cisco: Guia de Comandos

Um guia para cada modo de configuração: basta usar o comando show parser dump. Digite show parser dump <mode>, usando um dos modos de configuração (ex., interface, router…):

RouterA#sh parser dump router
 Mode Name :router
0 no protocol shutdown
0 no mpls ldp sync
0 no mpls ldp autoconfig area <address>
0 no mpls ldp autoconfig area <0-4294967295>
0 no mpls ldp autoconfig
0 no mpls traffic-eng router-id
0 no mpls traffic-eng multicast-intact
0 no mpls traffic-eng area <0-4294967295>
0 no mpls traffic-eng scanner interval
0 no mpls traffic-eng scanner max-flash
0 no mpls traffic-eng scanner
0 no mpls traffic-eng level-1
0 no mpls traffic-eng level-2
0 no mpls traffic-eng
0 no max-area-addresses
0 no net <address>
0 no is-type
...

Para um maior detalhe, use o parametro extend.

fonte: http://www.ciscoblog.com/archives/2008/06/cisco_command_r.html

 

Cisco: show ip bgp com expressões regulares (regexp)

Para exibir rotas BGP com filtro, basta utilizar o comando show ip bgp regexp [regexp].

Exemplo (exibindo apenas as rotas originadas no AS local):


RouterA#sh ip bgp regexp ^$
BGP table version is 33242, local router ID is 10.1.0.134
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
* i10.50.16.0/24    10.5.0.98                0    100      0 i
*>                  0.0.0.0                  0         32768 i
*> 10.1.0.134/32    0.0.0.0                  0         32768 i
*>i10.1.0.135/32    10.5.0.98                0    100      0 i

Mais exemplos aqui.

 

Cálculo com endereço IP no Excel - parte 2

Para conversão da notação em barra (/23) para máscara (255.255.254.0), copie e cole o bloco abaixo no Excel na célula A1:

192.168.32.160/23
Mask Calculation
=RIGHT(A1;LEN(A1)-FIND("/";A1))
=2^32-(2^(32-A3))
=DEC2HEX(A4;8 )
=MID($A$5;1;2)
=MID($A$5;3;2)
=MID($A$5;5;2)
=MID($A$5;7;2)
=HEX2DEC(A6)&"."&HEX2DEC(A7)&"."&HEX2DEC(A8)&"."&HEX2DEC(A9)
=-HEX2DEC(A6)-1
=-HEX2DEC(A7)-1
=-HEX2DEC(A8)-1
=-HEX2DEC(A9)-1
=RIGHT(DEC2HEX(A11);2)
=RIGHT(DEC2HEX(A12);2)
=RIGHT(DEC2HEX(A13);2)
=RIGHT(DEC2HEX(A14);2)
=HEX2DEC(A15)&"."&HEX2DEC(A16)&"."&HEX2DEC(A17)&"."&HEX2DEC(A18 )

A célula A10 mostrará a máscara correspondente e a célula 19, o wildcard.

 

Cisco: Key Sequences for Command Edit and Recall

Keyboard Command	What You Get
Up arrow or Ctrl-p	This displays the most recently used command. If it is pressed again, the next most recent command appears until the history buffer is exhausted. (The p stands for previous.)
Down arrow or Ctrl-n	If you have gone too far back into the history buffer, these keys will go forward to the more recently typed commands. (The n is for next.) Left arrow or Ctrl-b This moves the cursor backward in the currently displayed command without deleting characters. (The b stands for back.)
Right arrow or Ctrl-f	This moves the cursor forward in the currently displayed command without deleting characters. (The f stands for forward.)
Backspace	This moves the cursor backward in the currently displayed command, deleting characters.
Ctrl-a	This moves the cursor directly to the first character of the currently displayed command.
Ctrl-e	This moves the cursor directly to the end of the currently displayed command.
Esc-b	This moves the cursor back one word in the currently displayed command.
Esc-f	This moves the cursor forward one word in the currently displayed command.
Ctrl-r	This creates a new command prompt, followed by all the characters typed since the last command prompt was written. This is particularly useful if system messages confuse the screen and it is unclear what you have typed so far.

 

Bash prompt - PS1

Para mostrar o diretório atual e o hostname no prompt do bash:

bash$ PS1='\r\n[\w]\r\n\h> '

[~/dir/abc]
thehost>

 

Cisco: Envio de rotas através de tunel - GRE + OSPF

ROUTER A - Anuncia a rota default:

!
interface Tunnel0
 description Tunnel to RouterB
 ip unnumbered Loopback0
 ip tcp adjust-mss 1436
 ip ospf 50 area 0
 tunnel source Loopback0
 tunnel destination 10.2.2.2
!
router ospf 50
 router-id 10.1.1.1
 log-adjacency-changes
 passive-interface default
 no passive-interface Tunnel0
 default-information originate
!

ROUTER B - Recebe a rota defaul via ospf:

!
interface Tunnel0
 description Tunnel to RouterB
 ip unnumbered Loopback0
 ip tcp adjust-mss 1436
 ip ospf 50 area 0
 tunnel source Loopback0
 tunnel destination 10.1.1.1
!
router ospf 50
 router-id 10.2.2.2
 log-adjacency-changes
 passive-interface default
 no passive-interface Tunnel0
 distance 1
!

Distance = 1 faz com que a rota default recebida por este processo OSPF tenha preferência sobre qualquer outro protocolo.

Não foi usado o comando ‘keepalive’ no tunel pois há o keepalive (hello packets) do ospf.

 

Cálculo com endereço IP no Excel

Para somar (ou subtrair) valor de um endereço IP:

=LEFT(A1;FIND("x";Substitute(A1;".";"x";3))-1)&"."
&(MID(A1;FIND("x";Substitute(A1;".";"x";3))+1;3) + 1)

Onde A1 é a celula com o valor original e o valor a ser somado é o último número da fórmula (no exemplo, +1).

fonte: Chip Pearson, 2000-08-15 extraído de http://www.mvps.org/dmcritchie/excel/sorttcp.htm