Configuring Global Parameters
- Straight Polarity: If Mag-jack RJ45 connector has a dot or digit marked on front housing, it can be used with any type of cables.
- Reversed Polarity: If Mag-jack RJ45 connector has no dots or digit marked on front housing, it can be used with coupler and short cable (Cat5E UTP cable) to connect other devices which doesn’t support auto polarity correction.
The loopback interface in this sample configuration is used to support Network Address Translation (NAT) on the virtual-template interface. This configuration example shows the loopback interface configured on the gigabit ethernet interface with an IP address of 188.8.131.52/24, which acts as a static IP address. The loopback interface points back to virtual-template1, which has a negotiated IP address.
Static routes provide fixed routing paths through the network. They are manually configured on the router. If the network topology changes, the static route must be updated with a new route. Static routes are private routes unless they are redistributed by a routing protocol.
In the following configuration example, the static route sends out all IP packets with a destination IP address of 192.168.1.0 and a subnet mask of 255.255.255.0 on the Gigabit Ethernet interface to another device with an IP address of 10.10.10.2. Specifically, the packets are sent to the configured PVC.
The Cisco routers can use IP routing protocols, such as Routing Information Protocol (RIP) or Enhanced Interior Gateway Routing Protocol (EIGRP), to learn routes dynamically. You can configure either of these routing protocols on your router.
- During ROMMON initialization
- For loading a specific configuration file without accessing the router IOS prompt after IOS is up and running.
Table 2-1 shows the high level functionality when the push button is pressed during ROMMON initialization.
If you press the push button for more than three seconds and then release the push button after IOS is up and running, IOS detects this event and looks for configuration files in the order of priority.If the IOS finds the configuration file, it copies the configuration file to the startup configuration file. Then the router reloads itself and the new configuration takes effect. If the configuration files cannot be found, pressing reset button has no effect.
The Zero Touch Deployment (ZTD) through USB feature in Cisco 800M Series ISRs is an ease-of-use feature that loads a customized configuration from a USB flash drive. This feature requires that the router has no startup configuration in its nonvolatile RAM (NVRAM). The feature also requires that a valid configuration file, with the filename extension.cfg, is stored in the USB flash drive. A valid configuration file can be created by saving the running configuration of a router to flash, USB flash, or to a TFTP Server.
When a router with no startup configuration boots up, it checks for a valid configuration file within the USB flash drive. The pre-requisites for deployment using the Zero Touch Deployment through USB feature are:
- Boot up router with no startup-configuration.
- Cisco USB flash drive inserted in the first available USB slot.
- A valid configuration file in ASCII text with the filename extension.cfg
If the USB flash drive has multiple.cfg files, the router chooses the one with the highest index number in the USB Flash drive. To avoid loading an incorrect.cfg file, ensure that there is only one.cfg file in the USB flash drive.
The Cisco 800M Series ISR uses second core and it is actively used in detecting USB flash drive if 3G Wireless WAN module is present on the router. If 3G Wireless WAN module is not present, USB flash drive is detected by the IOS. When 3G Wireless WAN module is present, USB detection is a bit delayed for the Cisco 800M series ISR due to the delay in second core initialization. While system startup is in progress and push button is pressed, a timer is started to check the completion of second core initialization. For some reason if second core takes more time, system reports an error message and continues the normal start up. After second core initialization router waits up to 10 seconds for USB detection and then complete the configuration. In case the USB flash drive does not contain a deployment configuration, router enters the configuration mode.