Cisco switch default gateway configuration with example
We configure the default gateway on the end devices like PCs, servers, etc. However, we can assign the default gateway to the Cisco switch as well.
The default gateway allows the switch to establish connectivity with the outside network.
IP connectivity with the switch from a different network allows the network admin to manage the device from a remote location.
If administrators want to connect with the switch from the local network using telnet then they don’t need the default gateway however, reaching the switch from other subnets requires IP connectivity which is only possible through default gateway configuration.
We have to make sure that the default gateway IP address is assigned from the same subnet that has been configured for virtual VLAN.
E.g. Interface VLAN 1 IP address and default gateway IP address should be on the same network because network administrators use the interface VLAN IP addresses to telnet into the switch.
The following lab is showing the telnet connectivity from the local network.
In this lab, we can telnet switch0 from PC0 with the default gateway on the local network however, telnet from PC1 will not work as we have not yet configured the default gateway on the switch.
The following lab shows the telnet connectivity from different networks.
In this lab, we can see that after configuring the default gateway, telnet is working from PC1 as well which is the situation on another network that is connected via router.
IP default-gateway
We can use the IP default gateway on the global configuration mode to configure the default gateway on the Cisco switch.
We cannot reach out to the VLAN 1 interface of the switch without configuring the default gateway so if the connectivity is proper then we should be able to ping and if pinging is working fine then the telnet will also work.
If our network is reachable from the internet then we can also telnet to our switch using the internet however we have to make sure that proper security has been implemented on our internal network to prevent cyber attacks from the internet.
We should use secure connections like VPN while managing our network devices from the internet. Other security measures should also be implemented like firewall, antivirus etc to ensure the security of our internal network.