interVLAN routing su C887VA-K9

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Moderatore: Federico.Lagni

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iNGE
n00b
Messaggi: 1
Iscritto il: sab 27 feb , 2016 2:12 pm

Ciao a tutti,

ho un cisco c887va-k9 con 3 vlan: di solito il routing tra vlan funziona perfettamente, ma mi sono accorto grazie ad un disservizio di adsl telecom che esiste una situazione per cui l'intervlan routing non va e avrei la curiosità di capire il motivo. Grazie anticipatamente a tutti!

Situazione: cisco c887va-k9 che sulla FA0 ha un trunk per le varie vlan. Adsl telecom con ip dinamico.

Problema: quando ADSL è ok, e quindi le interfacce dialer e virtual-access sono UP, l'intervlan routing nella LAN funziona. Quando ADSL non va, e quindi dialer non ha un indirizzo ip e virtual-access non c'è, mi sono accorto che nemmeno l'intervlan routing funziona... e secondo me non dovrebbero influenzarsi a vicenda!

Riporto di seguito:
  • estratto della parte pertinente della configurazione
  • sh ip int brief con adsl ok
  • sh ip int brief senza adsl
  • sh ip route con adsl ok
  • sh ip route senza adsl
show running config (estratto):

Codice: Seleziona tutto

version 15.5

interface ATM0
 no ip address
 no atm ilmi-keepalive
 pvc 8/35 
  pppoe-client dial-pool-number 1
  pppoe-client ppp-max-payload 1500
 !
!
interface FastEthernet0
 description trunk verso lo switch
 switchport trunk native vlan 100
 switchport mode trunk
 no ip address
!
interface Vlan10
 ip address 172.16.10.1 255.255.255.0
 ip mtu 1492
 ip nat inside
 ip virtual-reassembly in
 ip tcp adjust-mss 1452
!
interface Vlan20
 ip address 172.16.20.1 255.255.255.0
 ip mtu 1492
 ip nat inside
 ip virtual-reassembly in
 ip tcp adjust-mss 1452
!
interface Vlan30
 ip address 172.16.30.1 255.255.255.0
 ip mtu 1492
 ip nat inside
 ip virtual-reassembly in
 ip tcp adjust-mss 1452
!
interface Vlan100
 no ip address
!
interface Dialer1
 ip address negotiated
 no ip redirects
 no ip unreachables
 no ip proxy-arp
 ip nat outside
 ip virtual-reassembly in
 encapsulation ppp
 dialer pool 1
 dialer-group 1
 ppp authentication chap pap callin
 ppp chap hostname aliceadsl
 ppp chap password 0 aliceadsl
 ppp pap sent-username aliceadsl password 0 aliceadsl
 ppp ipcp dns request accept
 no cdp enable
!
ip nat inside source list NAT_ACL interface Dialer1 overload
ip route 0.0.0.0 0.0.0.0 Dialer1
!
sh ip int brief (adsl OK!!!):

Codice: Seleziona tutto

router#sh ip int brief
Interface                  IP-Address      OK? Method Status                Protocol
ATM0                       unassigned      YES NVRAM  up                    up      
Dialer1                    87.13.45.210    YES IPCP   up                    up      
Ethernet0                  unassigned      YES NVRAM  administratively down down    
FastEthernet0              unassigned      YES unset  up                    up      
FastEthernet1              unassigned      YES unset  down                  down    
FastEthernet2              unassigned      YES unset  down                  down    
FastEthernet3              unassigned      YES unset  down                  down    
NVI0                       unassigned      YES unset  administratively down down    
Virtual-Access1            unassigned      YES unset  up                    up      
Vlan1                      unassigned      YES unset  up                    up      
Vlan10                     172.16.10.1     YES NVRAM  up                    up      
Vlan20                     172.16.20.1     YES NVRAM  up                    up      
Vlan30                     172.16.30.1     YES NVRAM  up                    up      
Vlan100                    unassigned      YES unset  up                    up      
router#
sh ip int brief (adsl non va):

Codice: Seleziona tutto

router#sh ip int brief 
Interface                  IP-Address      OK? Method Status                Protocol
ATM0                       unassigned      YES NVRAM  up                    up      
Dialer1                    unassigned      YES NVRAM  up                    up      
Ethernet0                  unassigned      YES NVRAM  administratively down down    
FastEthernet0              unassigned      YES unset  up                    up      
FastEthernet1              unassigned      YES unset  down                  down    
FastEthernet2              unassigned      YES unset  down                  down    
FastEthernet3              unassigned      YES unset  down                  down    
NVI0                       unassigned      YES unset  administratively down down    
Vlan1                      unassigned      YES unset  up                    up      
Vlan10                     172.16.10.1     YES NVRAM  up                    up      
Vlan20                     172.16.20.1     YES NVRAM  up                    up      
Vlan30                     172.16.30.1     YES NVRAM  up                    up      
Vlan100                    unassigned      YES unset  up                    up      
router#
sh ip route (adsl OK!!!):

Codice: Seleziona tutto

router#sh ip route
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
       a - application route
       + - replicated route, % - next hop override

Gateway of last resort is 0.0.0.0 to network 0.0.0.0

S*    0.0.0.0/0 is directly connected, Dialer1
      87.0.0.0/32 is subnetted, 1 subnets
C        87.13.45.210 is directly connected, Dialer1
      172.16.0.0/16 is variably subnetted, 6 subnets, 2 masks
C        172.16.10.0/24 is directly connected, Vlan10
L        172.16.10.1/32 is directly connected, Vlan10
C        172.16.20.0/24 is directly connected, Vlan20
L        172.16.20.1/32 is directly connected, Vlan20
C        172.16.30.0/24 is directly connected, Vlan30
L        172.16.30.1/32 is directly connected, Vlan30
      192.168.100.0/32 is subnetted, 1 subnets
C        192.168.100.1 is directly connected, Dialer1
router#
sh ip route (adsl non va):

Codice: Seleziona tutto

router#sh ip route
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
       a - application route
       + - replicated route, % - next hop override

Gateway of last resort is 0.0.0.0 to network 0.0.0.0

S*    0.0.0.0/0 is directly connected, Dialer1
      172.16.0.0/16 is variably subnetted, 6 subnets, 2 masks
C        172.16.10.0/24 is directly connected, Vlan10
L        172.16.10.1/32 is directly connected, Vlan10
C        172.16.20.0/24 is directly connected, Vlan20
L        172.16.20.1/32 is directly connected, Vlan20
C        172.16.30.0/24 is directly connected, Vlan30
L        172.16.30.1/32 is directly connected, Vlan30
router#
Cosa mi sfugge?

grazie a tutti,
Andrea.
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