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Conguring Filters with a Sequence Number
To congure lters with a sequence number, use the following commands.
1 Enter IP ACCESS LIST mode by creating an extended IP ACL.
CONFIGURATION mode
ip access-list extended access-list-name
2 Congure a drop or forward lter.
CONFIG-EXT-NACL mode
seq sequence-number {deny | permit} {ip-protocol-number | icmp | ip | tcp | udp} {source mask
| any | host ip-address} {destination mask | any | host ip-address} [operator port [port]]
[count [byte] | log] [order] [monitor [session-id]] [fragments]
When you use the log keyword, the CP logs details about the packets that match. Depending on how many packets match the log entry
and at what rate, the CP may become busy as it has to log these packets’ details.
When you create the lters with a specic sequence number, you can create the lters in any order and the lters are placed in the correct
order.
NOTE: When assigning sequence numbers to lters, keep in mind that you might need to insert a new lter. To prevent
reconguring multiple lters, assign sequence numbers in multiples of ve or another number.
The following example shows how the seq command orders the lters according to the sequence number assigned. In the example, lter
15 was congured before lter 5, but the
show config command displays the lters in the correct order.
Dell(config-ext-nacl)#seq 15 deny ip host 112.45.0.0 any log
Dell(config-ext-nacl)#seq 5 permit tcp 12.1.3.45 0.0.255.255 any monitor 209
Dell(config-ext-nacl)#show config
!
ip access-list extended dilling
seq 5 permit tcp 12.1.0.0 0.0.255.255 any monitor 209
seq 15 deny ip host 112.45.0.0 any log
Dell(config-ext-nacl)#
Conguring Filters Without a Sequence Number
If you are creating an extended ACL with only one or two lters, you can let Dell Networking OS assign a sequence number based on the
order in which the lters are congured. Dell Networking OS assigns lters in multiples of ve.
To congure a lter for an extended IP ACL without a specied sequence number, use any or all of the following commands:
• Congure a deny or permit lter to examine IP packets.
CONFIG-EXT-NACL mode
{deny | permit} {source mask | any | host ip-address} [count [byte]] [order] [monitor
[session-id]] [fragments]
• Congure a deny or permit lter to examine TCP packets.
CONFIG-EXT-NACL mode
{deny | permit} tcp {source mask] | any | host ip-address}} [count [byte]] [order] [monitor
[session-id]] [fragments]
• Congure a deny or permit lter to examine UDP packets.
CONFIG-EXT-NACL mode
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Access Control Lists (ACLs)