Browsing articles from "April, 2011"
Apr
30
2011

Speed up your reload

How long does it take to reload your router? 3 or 4 minutes? Do you know that is possible to speed up your reboot? If your answer is negative, read how warm reload is faster than cold (classic) reload. Introduced in Cisco IOS Release 12.3(2)T, the warm reload feature allows users to reload their routers without reading images from storage. That is, the Cisco IOS image reboots without ROM monitor mode (ROMMON) intervention by restoring the read-write data from a previously saved copy in the RAM and by starting execution without either copying the image from flash to RAM or [...]

Apr
28
2011

How to schedule a reload

Not everyone knows that the reload command permits to schedule a reboot system; for instance, to plan a night router restart or during a critical configuration (AAA, vty, and so on…). There are two ways to schedule a reload system: at: at a specific time/date in: after a time interval The ‘at’ keyword permits to schedule a reload of the software to take place at the specified time (using a 24-hour clock). If you specify the month and day, the reload is scheduled to take place at the specified time and date. The following example reloads the router on April [...]

Apr
26
2011

IPsec VPN: EzVPN, GRE, DMVPN, VTI, GETVPN

Internet Protocol Security (IPsec) is a protocol suite for securing Internet Protocol (IP) communications by authenticating and encrypting each IP packet of a communication session. IPsec also includes protocols for establishing mutual authentication between agents at the beginning of the session and negotiation of cryptographic keys to be used during the session. IPsec is an end-to-end security scheme operating in the Internet Layer of the Internet Protocol Suite. It can be used in protecting data flows between a pair of hosts (host-to-host), between a pair of security gateways (network-to-network), or between a security gateway and a host (network-to-host). There are [...]

Apr
5
2011

March 2011: two Cisco vulnerabilities

The Cisco Product Security Incident Response Team (PSIRT) has published two important vulnerability advisories: Cisco Network Admission Control Guest Server System Software Authentication Bypass Vulnerability Cisco Secure Access Control System Unauthorized Password Change Vulnerability Cisco Network Admission Control Guest Server System Software Authentication Bypass Vulnerability Cisco Network Admission Control (NAC) Guest Server system software contains a vulnerability in the RADIUS authentication software that may allow an unauthenticated user to access the protected network.