Filter
Top Products
Configuring IP Services
IP Services Configuration Examples
IPC-125
Cisco IOS IP Configuration Guide
IP Extended Access List with Fragment Control Example
The first statement will match and deny only noninitial fragments destined for host 1.1.1.1. The second
statement will match and permit only the remaining nonfragmented and initial fragments that are
destined for host 1.1.1.1 TCP port 80. The third statement will deny all other traffic. In order to block
noninitial fragments for any TCP port, we must block noninitial fragments for all TCP ports, including
port 80 for host 1.1.1.1.
access-list 101 deny ip any host 1.1.1.1 fragments
access-list 101 permit tcp any host 1.1.1.1 eq 80
access-list 101 deny ip any any
Time Range Applied to an IP Access List Example
The following example denies HTTP traffic on Monday through Friday from 8:00 a.m. to 6:00 p.m. on
IP. The example allows UDP traffic on Saturday and Sunday from noon to 8:00 p.m. only.
time-range no-http
periodic weekdays 8:00 to 18:00
!
time-range udp-yes
periodic weekend 12:00 to 20:00
!
ip access-list extended strict
deny tcp any any eq http time-range no-http
permit udp any any time-range udp-yes
!
interface ethernet 0
ip access-group strict in
Commented IP Access List Entry Examples
In the following example of a numbered access list, the workstation belonging to Jones is allowed access
and the workstation belonging to Smith is not allowed access:
access-list 1 remark Permit only Jones workstation through
access-list 1 permit 171.69.2.88
access-list 1 remark Do not allow Smith workstation through
access-list 1 deny 171.69.3.13
In the following example of a numbered access list, the Winter and Smith workstations are not allowed
to browse the web:
access-list 100 remark Do not allow Winter to browse the web
access-list 100 deny host 171.69.3.85 any eq http
access-list 100 remark Do not allow Smith to browse the web
access-list 100 deny host 171.69.3.13 any eq http
In the following example of a named access list, the Jones subnet is not allowed access:
ip access-list standard prevention
remark Do not allow Jones subnet through
deny 171.69.0.0 0.0.255.255
In the following example of a named access list, the Jones subnet is not allowed to use outbound Telnet:
ip access-list extended telnetting
remark Do not allow Jones subnet to telnet out