Configuring MED: Multiple Adjacent Autonomous Systems
By default, a Cisco router ignores MED when the multiple routes to a single NLRI list different neighboring ASNs. This default action makes sense—normally you would not expect two different neighboring ISPs to have chosen to work together to set MEDs. To override this default and consider the MED in all cases, a router needs to configure the bgp always-compare-med BGP subcommand. If used on one router, all routers inside the same AS should also use the bgp always-compare-me..
Default Only, Primary, and Backup
In this case, the customer can follow defaults toward the provider. One link is used as primary, and the second link is used as backup. Figure 7-14 illustrates a relevant situation. Figure 7-14. Multihoming to Two Providers A customer can set or learn the default routes to the two providers either through static routesor through both providers' dynamic advertisements of default routes. The customer can preferone default over another by using administrative distance or ..
The default data rate setting on access points is generally auto, which allows radio cards to use any of the data rates of the given physical layer. For example, 802.11b allows data rates of 1, 2, 5.5, and 11 Mbps. The 802.11g standard extends these data rates up to 54 Mbps. The radio card usually attempts to send data frames at the highest supported rate, such as 11 Mbps for 802.11b stations and 54 Mbps for 802.11g stations. When set to auto, the radio card automatica..
Avoid Security Through Obscurity
When reviewing publications and commentary about security principles, you frequently encounter the postulate "security through obscurity is not security." Although it is said often, it is frequently misunderstood and is used as an excuse or justification for all sorts of security ills. Let's consider a few scenarios to better understand this axiom: • Paper currency is the basis for many of our day-to-day transactions, and counterfeiting is an ongoing concern. Nations ..
Routing Multicast Traffic with MOSPF
Unfortunately, Cisco does not support MOSPF. As mentioned in the Introduction to this chapter, MOSPF is a set of multicast extensions to OSPF that uses LSA Type 6. By default, when a Cisco router receives a Type 6 LSA packet it will generate a %OSPF- 4-BADLSATYPE error message. To avoid this error message, you can configure your routers to ignore Type 6 LSA packets: Router#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)..
