2

You can see the topology in the picture below. I’ve configured the management VLAN on the switch to be VLAN 999 to separate the management traffic from user traffic. I’ve also configured SVI 999 with an IP address of 10.10.10.2/24. The default gateway is already configured on the switch as well (which is 10.10.10.1, pointing to the router’s subinterface).

I think I’ve done everything correctly, but I still can’t reach 10.10.10.2 from PC2 to configure the switch.

What is wrong?

Thanks in advance!

Router Configurations:

interface GigabitEthernet0/0
 no ip address
 duplex auto
 speed auto
 media-type rj45
!
interface GigabitEthernet0/0.10
 encapsulation dot1Q 10
 ip address 192.168.10.1 255.255.255.0
!
interface GigabitEthernet0/0.20
 encapsulation dot1Q 20
 ip address 192.168.20.1 255.255.255.0
!
interface GigabitEthernet0/0.999
 encapsulation dot1Q 999
 ip address 10.10.10.1 255.255.255.0
!
interface GigabitEthernet0/1
 ip address 172.16.1.1 255.255.255.0
 duplex auto
 speed auto
 media-type rj45
!

Output of show ip route command:

Gateway of last resort is not set

      10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        10.10.10.0/24 is directly connected, GigabitEthernet0/0.999
L        10.10.10.1/32 is directly connected, GigabitEthernet0/0.999
      172.16.0.0/16 is variably subnetted, 2 subnets, 2 masks
C        172.16.1.0/24 is directly connected, GigabitEthernet0/1
L        172.16.1.1/32 is directly connected, GigabitEthernet0/1
      192.168.10.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.10.0/24 is directly connected, GigabitEthernet0/0.10
L        192.168.10.1/32 is directly connected, GigabitEthernet0/0.10
      192.168.20.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.20.0/24 is directly connected, GigabitEthernet0/0.20
L        192.168.20.1/32 is directly connected, GigabitEthernet0/0.20

Switch Configurations:

interface GigabitEthernet0/0
 switchport trunk encapsulation dot1q
 switchport mode trunk
 negotiation auto
!
interface GigabitEthernet0/1
 switchport access vlan 10
 switchport mode access
 negotiation auto
!
interface GigabitEthernet0/2
 switchport access vlan 20
 switchport mode access
 negotiation auto
!
interface Vlan999
 ip address 10.10.10.1 255.255.255.0
!
ip default-gateway 10.10.10.1

Output of show inter trunk & show ip inter br:

Switch#show interfaces trunk 

Port        Mode             Encapsulation  Status        Native vlan
Gi0/0       on               802.1q         trunking      1

Port        Vlans allowed on trunk
Gi0/0       1-4094

Port        Vlans allowed and active in management domain
Gi0/0       1,10,20,999

Port        Vlans in spanning tree forwarding state and not pruned
Gi0/0       1,10,20,999
Switch#show ip interface brief 
Interface              IP-Address      OK? Method Status                Protocol
GigabitEthernet0/0     unassigned      YES unset  up                    up      
GigabitEthernet0/1     unassigned      YES unset  up                    up      
GigabitEthernet0/2     unassigned      YES unset  up                    up      
GigabitEthernet0/3     unassigned      YES unset  down                  down    
GigabitEthernet1/0     unassigned      YES unset  down                  down    
GigabitEthernet1/1     unassigned      YES unset  down                  down    
GigabitEthernet1/2     unassigned      YES unset  down                  down    
GigabitEthernet1/3     unassigned      YES unset  down                  down    
GigabitEthernet2/0     unassigned      YES unset  down                  down    
GigabitEthernet2/1     unassigned      YES unset  down                  down    
GigabitEthernet2/2     unassigned      YES unset  down                  down    
GigabitEthernet2/3     unassigned      YES unset  down                  down    
GigabitEthernet3/0     unassigned      YES unset  down                  down    
GigabitEthernet3/1     unassigned      YES unset  down                  down    
GigabitEthernet3/2     unassigned      YES unset  down                  down    
GigabitEthernet3/3     unassigned      YES unset  down                  down
Vlan999                10.10.10.1      YES manual up                    up

Here's what happens when i try to ping 10.10.10.1 from PC1:

PC1>ping 10.10.10.1

10.10.10.2 icmp_seq=1 timeout
10.10.10.2 icmp_seq=2 timeout
10.10.10.2 icmp_seq=3 timeout
10.10.10.2 icmp_seq=4 timeout
10.10.10.2 icmp_seq=5 timeout

PC1 Configurations:

NAME        : PC1[1]
IP/MASK     : 192.168.10.10/24
GATEWAY     : 192.168.10.1
DNS         : 
MAC         : 00:50:79:66:68:00
LPORT       : 10010
RHOST:PORT  : 127.0.0.1:10011
MTU         : 1500

enter image description here

Improve this question
3
  • Please add sufficient detail to your question. We'd need to see the configurations of the router and the switch (in text format, using the editor's {} preformat option). Make sure we can see what connects where. Commented Feb 1, 2025 at 8:24
  • @Zac67 Is it sufficient now? :) Commented Feb 1, 2025 at 9:06
  • Your interfaces are not named and we still cannot see how each port is used. Commented Feb 1, 2025 at 10:42

1 Answer 1

Reset to default
7

You have a typo! A second pair of eyes is all you need. You mistakenly configured 10.10.10.1 on both sides of VLAN 999, instead of putting 10.10.10.2 on the switch side.

router:

interface GigabitEthernet0/0.999
 encapsulation dot1Q 999
 ip address 10.10.10.1 255.255.255.0

switch:

interface Vlan999
 ip address 10.10.10.1 255.255.255.0
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