Category Archives: Router

Configuring Date and Time on a Cisco 3750G Layer 3 Switch.

Posted on March 2, 2015 by jbernec

The lower end of Cisco switches e.g the C3750 Layer 3, do not have a built-in system clock mechanism. As a result, the time needs to be set either manually or by an external ntp time source. The configuration below … Continue reading →

Posted in Cisco, Cisco 3750G, Cisco IOS, Cisco Switch, Clock, IOS, NTP, Router, Switch, Telnet, Time | Tagged , , , , , , | Leave a comment

Configuring NAT (Network Address Translation) on a Cisco 1921 Router.

Posted on March 11, 2014 by jbernec

These are the steps I would follow to configure NAT (Network Address Translation) on a Cisco 1921 Router. The tool of choice is Putty configured to log the commands. You could use the Cisco IOS context Help to assist with … Continue reading →

Posted in Access-Lists, Cisco, NAT, Network Address Translation, Router | Tagged , , , , | Leave a comment

Configuring InterVLAN Routing on a Layer 3 Switch and providing DHCP to multiple subnets Part 2

Posted on October 16, 2013 by jbernec

In part 2 of this topic, I will show how to configure the Switch Virtual Interfaces and IP Helper addresses on the Cisco 3750G EMI: L3Switch(config)#interface vlan 20 L3Switch(config-if)# ip address 10.0.2.1 255.255.255.0 (Configure IP Address on the vlan 20 … Continue reading →

Posted in Cisco, DHCP, IOS, Router, svi, Switch, Switch Virtual Interface, vlan | Tagged , , | 13 Comments

Configuring InterVLAN Routing on a Layer 3 Switch and providing DHCP to multiple subnets Part 1

Posted on September 26, 2013 by jbernec

In this series, I would like to post my practical experience in setting up multiple VLANs/subnets and using a Layer 3 switch to route traffic across them. The post will also include my configuration steps enabling the use of a … Continue reading →

Posted in Cisco, DHCP, Helper Address, IP, Router, svi, Switch, Switch Virtual Interface, vlan | Tagged , , , , | 3 Comments

How to Configure ssh on a Cisco Switch.

Posted on September 9, 2013 by jbernec

Telnet is a widely used protocol for accessing and administering Cisco devices. But this protocol is not exactly secure and transmits data over a network in plain text. Ssh is a secure protocol and it’s best practice to secure your … Continue reading →

Posted in Cisco, Router, ssh, Switch, Telnet | Leave a comment

Configuring Policy Based Routing on a Cisco 3750G EMI

Posted on September 8, 2013 by jbernec

So we recently restructured the Company network from a flat network to multiple Vlans. The need has arisen to route traffic for specific vlans through a different ISP for business reasons. This means routing traffic to a path different from … Continue reading →

Posted in ASA, Cisco, Firewall, IOS, Router, Switch | Leave a comment