Nota: Este Post faz parte do guide de Routing.
VRRP Defined
RFC 2338
Terms and Concepts
VRRP Router
Master Router
Backup Routers
Virtual Router
VRRP Communications
VRRP version 2
Usa Multicast 224.0.0.18
Default advertisement 1 segundo
E possível usar subsecond usando o comando fast-interval (o valor pode variar entre 100-999 milisegundos)
O MAC-ADDRESS do VIP tem o formato 00-00-5E-00-01-VRID
O Master state e elegido através da priority mais alta (entre 1 -255), by default e 100
Caso o router tenha o próprio VIP configurado como IP da interface deve ser configurado a priority 255 e ativado automaticamente o preempt.
Em ambientes onde o router não tem o próprio VIP como IP é possível desativar o preempt
VRRP States
Initialize
Master
Backup
Transition – Estado apenas transitório entre Backup e Master. Neste estado não existe forwarding
VRRP Configuration
set interfaces ge-0/0/4.0 family inet addres 172.25.100.2/24 vrrp-group 10 virtual-address 172.25.100.1 priority 200
outras opções:
track
accept-data – Permite que o master responda a ICMP com destino ao VIP. Caso o master tenha o proprio VIP responde by default a ICMP
authenticatioon-type – 3 types:none,simple,MD5
authenticatioon-key
no-preempt
É possível usar o inherit da config quando existem múltiplos grupos VRRP na mesma interface física usando assim algumas das mesmas características.
Com a opcao vrrp-inheret-from as características usadas são:advertise-interval, authentication-key, authentication-type, fast-interval, no-preempt, preempt, track interface, e track route
Unified ISSU
Apenas suportado em chassis com 2 REs e com os serviços GRES e NSR activos. Ambos os REs devem executar a mesma versão de software
Para iniciar o processo deve ser executado o comando request system software-in-service-upgrade no master RE
Para verificar o estados dos FPCs após o ultimo Unified ISSU:
user@host> show chassis in-service-upgrade
Item Status Reason
FPC 0 Online
FPC 1 Online
FPC 2 Online
PIC 0 Online
PIC 1 Online
FPC 3 Offline Offlined by CLI command
FPC 4 Online
PIC 1 Online
FPC 5 Online
PIC 0 Online
FPC 6 Online
PIC 3 Online
FPC 7 Online
!Cancelar o processo de upgrade (unified ISSU)
user@host> request system abort software-in-service-upgrade
Appendix A IPv6
Alguns dos benefícios do IPv6
More efficient routing
Quality of service (QoS)
Elimination of the NAT requirement
Network Layer security with end-to-end IPsec
Ease of management using stateless address autoconfiguration
Improved header format to reduce header overhead
O header IPv6 tem 40 bytes (fixos) e inclui os seguintes campos:
Version: 4-bit field containing the number 6, indicating IPv6
Traffic class: 8-bit field that determines the traffic priority
Flow label: 20-bit field used for QoS management
Payload length: 16-bit field indicates the size of the payload in octets
Next header: 8-bit field indicating the next encapsulated protocol
Hop limit : 8-bit field replaces the time-to-live (TTL) field in IPv4
Source address : 128 bits
Destination address: 128 bits
IPv6 Defines Six Extension Headers
As extensões possíveis no header:
Hop-by-hop options: Signifies that the options need to be examined by each node along the path of a packet
Routing: Provides a list of intermediate nodes that should be visited on the path to the packet’s destination
Fragment: Signals when a packet has been fragmented by the source
Destination options: Options examined only by the destination node , and capable of appearing twice in a packet
Authentication header: Used with IPsec to verify authenticity of a packet
Encrypted security payload: Used with IPsec and carries encrypted data for secure communication
IPv6 Address Types
3 Tipos de endereços IPv6:
• Unicast
• Multicast
• Anycast
Prefix Notation
O RFC4291 define as ultimas regras sobre prefix notation
::/128 : unspecified;
::1/128: This prefix notation should be used for the loopback;
FF00::/8 : Multicast
FE80::/10: Local-Link
Special Addresses
Link-Local Unicast Addresses – Prefix (10bits) + SubnetID (54bits) + Interface ID (64bits)
Site-Local Unicast Addresses – Enderecos Privatos a semelhanca do RFC1918 em IPv4. Prefix (10bits) + SubnetID (54bits) + Interface ID (64bits)
Global Unicast Addresses – Enderecos roteados na Internet. FP (3bits) + GlobalRouting Prefix (45bits) + SID (16bits) + Interface ID (64bits)
Stateless Autoconfiguration
Permitir atribuir IP automaticamente sem a necessidade de DHCP.
Stateless autoconfiguration consiste em varios elementos:
• Extended unique identifier (EUI)
• Router advertisement message
• Router solicitation message
• Prefix list
Neighbor Discovery (ND)
É o processo de tracking dos neighbors no mesmo local link.
O ND é opcional nos devices IPv6.
Após o host enviar um Router Solicitation (RS) o router confirma enviando um Router Advertisement (RA) com a prefix list. O host o endereçamento no prefix-list para efectuar a autoconfiguracao
Stateful Autoconfiguration
O DHCPv6 e conhecido como stateful, definido no RFC3315
set interfaces ge1/1/0.110 family inet6 address fec0:0:0:2003::1/64
lab@mxA-1# run show interfaces terse ge-1/1/0
Interface Admin Link Proto Local Remote
ge-1/1/0 up up
ge-1/1/0.110 up up inet 172.16.110.1/24
inet6 fe80::8271:1f00:6ec1:a278/64
fec0:0:0:2003::1/64
lab@mxA-1# run show route table inet6.0
inet6.0: 4 destinations, 4 routes (4 active, 0 holddown, 0 hidden)
Restart Complete
+ = Active Route, – = Last Active, * = Both
fe80::/64 *[Direct/0] 00:02:24
> via ge-1/1/0.110
fe80::8271:1f00:6ec1:a278/128
*[Local/0] 00:02:24
Local via ge-1/1/0.110
fec0:0:0:2003::/64 *[Direct/0] 00:02:24
> via ge-1/1/0.110
fec0:0:0:2003::1/128
*[Local/0] 00:02:24
Local via ge-1/1/0.110
lab@mxA-1# run show ipv6 neighbors
IPv6 Address Linklayer Address State Exp Rtr Secure Interface
fec0:0:0:2003::2 80:71:1f:c1:c3:78 reachable 34 yes no ge-1/1/0.110
IPv6 Multicast Address
No IPv6 o ICMPv6 é usado no multicast group management para optimizar o tráfego multicast. Este processo é referido como Multicast Listener Discovery (MLD)
Os enderecos multicast segundo o RFC 4291:
• Solicited-node multicast addresses are for Neighbor Solicitation (NS) messages;
• All-nodes multicast addresses are for Router Advertisement (RA) messages; and
• All-routers multicast addresses are for Router Solicitation (RS) messages.
IPv6 Anycast Address
Definido no RFC 2526
Permite que o mesmo IP esteja distribuído, mas apenas um Host irá receber o tráfego
set routing-options rib inet6.0 static route 0::/0 next-hop FEc0:0:0:2003::2 preference 250
OSPFv3 Configuration Example
O processo de selecao do RID no OSPFv3 e identico ao da v2, o RID continua a ser IPv4
Monitoring OSPFv3 Operations
show ospf3 neighbor
show ospf3 interface
show ospf3 database
show ospf3 route
IS-IS Configuration
set interfaces ge1/1/0.110 family iso
set interfaces ge1/1/0.110 family inet6 address fec0:0:0:2003::1/64
set interfaces lo0 unit 0 family iso address 49.0002.1111.1111.1111.00
set interfaces lo0 unit 0 family inet6 address fec0:0:0:1001::1/128
Monitoring IS-IS Operations
lab@mxA-1# run show isis interface
IS-IS interface database:
Interface L CirID Level 1 DR Level 2 DR L1/L2 Metric
ge-1/1/0.110 3 0x1 mxA-1.00 mxA-1.00 10/10
lo0.0 0 0x1 Passive Passive 0/0
[edit]
lab@mxA-1# run show isis adjacency
BGP Configuration
!eBGP Peering
set protocols bgp group ext-65501 type external
set protocols bgp group ext-65501 peer-AS 65501
set protocols bgp group ext-65501 neighbor fec0:0:0:2003::2
Monitoring BGP Operations
show bgp summary
Tunneling IPv6 Traffic
Por vezes e necessário encapsular trafego IPv6 em IPv4.
Alguns dos mecanismos de transicao
•IPv4-compatible addressing
•Configured tunnels
•6to4
•6over4
!Site A
set interface gr-0/0/0.0 tunnel source 172.16.110.1 destination 172.16.110.2
set interface gr-0/0/0.0 family inet6 address fec0:0:0:1000::1/126
set routing-options rib inet6.0 static route fec0:0:0:2000::/64 next-hop gr-0/0/0.0
set routing-options rib inet6.0 static route fec0:0:0:1001::/64 next-hop gr-0/0/0.0
!Site B
set interface gr-0/0/0.0 tunnel source 172.16.110.2 destination 172.16.110.1
set interface gr-0/0/0.0 family inet6 address fec0:0:0:1000::2/126
set routing-options rib inet6.0 static route fec0:0:0:2000::/64 next-hop gr-0/0/0.0
set routing-options rib inet6.0 static route fec0:0:0:1001::/64 next-hop gr-0/0/0.0
Referências:
Notas estudo JNCIS-ENT parte 1
Notas estudo JNCIS-ENT parte 2
Notas estudo JNCIS-ENT parte 3
Notas estudo JNCIS-ENT parte 4
Notas estudo JNCIS-ENT parte 5
Notas estudo JNCIS-ENT parte 6
Notas estudo JNCIS-ENT parte 7
Notas estudo JNCIS-ENT parte 8
Notas estudo JNCIS-ENT parte 9
Notas estudo JNCIS-ENT parte 10
Notas estudo JNCIS-ENT parte 11
Notas estudo JNCIS-ENT parte 12
Notas estudo JNCIS-ENT parte 13
Notas estudo JNCIS-ENT parte 14