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seq sequence-number {deny | permit} tcp {source mask | any | host ip-address} [count [byte]]
[order] [fragments]
Example of the seq Command
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, you may have to insert a new lter. To prevent reconguring multiple lters,
assign sequence numbers in multiples of ve or another number.
The example below 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
Dell(config-ext-nacl)#show confi
!
ip access-list extended dilling
seq 5 permit tcp 12.1.0.0 0.0.255.255 any
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 the system assign a sequence number based on the order in
which the lters are congured. Filters are assigned 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] [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] [fragments]
• Congure a deny or permit lter to examine UDP packets.
CONFIG-EXT-NACL mode
{deny | permit} udp {source mask | any | host ip-address}} [count [byte]] [order] [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.
The following example shows an extended IP ACL in which the sequence numbers were assigned by the software. The lters were
assigned sequence numbers based on the order in which they were congured (for example, the rst lter was given the lowest sequence
number). The show config command in IP ACCESS LIST mode displays the two lters with the sequence numbers 5 and 10.
Example of Viewing Filter Sequence for a Specied Extended ACL
Dell(config-ext-nacl)#deny tcp host 123.55.34.0 any
Dell(config-ext-nacl)#permit udp 154.44.123.34 0.0.255.255 host 34.6.0.0
Dell(config-ext-nacl)#show config
!
ip access-list extended nimule
seq 5 deny tcp host 123.55.34.0 any
seq 10 permit udp 154.44.0.0 0.0.255.255 host 34.6.0.0
Dell(config-ext-nacl)#
Access Control Lists (ACLs)
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