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Dell(config-ext-nacl)#end
Dell#show ip accounting access-list
!
Extended Ingress IP access list abcd on Loopback 0
seq 5 permit tcp any any
seq 10 deny icmp any any
seq 10 deny icmp any any
For more information, refer to the VTY Line Local Authentication and Authorization section in the Securitychapter.
IP Prex Lists
IP prex lists control routing policy.
An IP prex list is a series of sequential lters that contain a matching criterion (examine IP route prex) and an action (permit or deny) to
process routes. The lters are processed in sequence so that if a route prex does not match the criterion in the rst lter, the second lter
(if congured) is applied. When the route prex matches a lter, Dell Networking OS drops or forwards the packet based on the lter’s
designated action. If the route prex does not match any of the lters in the prex list, the route is dropped (that is, implicit deny).
A route prex is an IP address pattern that matches on bits within the IP address. The format of a route prex is A.B.C.D/X where A.B.C.D
is a dotted-decimal address and /X is the number of bits that should be matched of the dotted decimal address. For example, in
112.24.0.0/16, the rst 16 bits of the address 112.24.0.0 match all addresses between 112.24.0.0 to 112.24.255.255.
The following examples show permit or deny lters for specic routes using the le and ge parameters, where x.x.x.x/x represents a route
prex:
• To deny only /8 prexes, enter deny x.x.x.x/x ge 8 le 8.
• To permit routes with the mask greater than /8 but less than /12, enter permit x.x.x.x/x ge 8.
• To deny routes with a mask less than /24, enter deny x.x.x.x/x le 24.
• To permit routes with a mask greater than /20, enter permit x.x.x.x/x ge 20.
The following rules apply to prex lists:
• A prex list without any permit or deny lters allows all routes.
• An “implicit deny” is assumed (that is, the route is dropped) for all route prexes that do not match a permit or deny lter in a
congured prex list.
• After a route matches a lter, the lter’s action is applied. No additional lters are applied to the route.
Implementation Information
In Dell Networking OS, prex lists are used in processing routes for routing protocols (for example, router information protocol [RIP], open
shortest path rst [OSPF], and border gateway protocol [BGP]).
It is important to know which protocol your system supports prior to implementing prex-lists.
NOTE
: The S5000 platform does not support all protocols. It is important to know which protocol you are supporting prior to
implementing Prex-Lists.
Conguration Task List for Prex Lists
To congure a prex list, use commands in PREFIX LIST, ROUTER RIP, ROUTER OSPF, and ROUTER BGP modes.
Create the prex list in PREFIX LIST mode and assign that list to commands in ROUTER RIP, ROUTER OSPF and ROUTER BGP modes.
The following list includes the conguration tasks for prex lists, as described in the following sections.
• Creating a Prex List
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Access Control Lists (ACLs)