noobregistry.blogg.se - Permit ssh on mac

Hence having exception for destination port 23 on access-list applied to up-link ports is important (Assuming we are connected to switch using telnet). Specially while configuring access list to switch port through which we are connected to switch (mostly up-link port). It is important to ensure that telnet access to switch does not get blocked by the access-list that we are trying to apply.However if we want to apply very specific and detailed access list as given above only on one port (probably up-link) then that will not cause any problem.

Hence if we want to apply access lists on many ports then they must be small. access-list 102 permit udp any any Then we may not be able to apply them on many ports.

If access lists are very big and descriptive likeĬonfig t no access-list 102 access-list 102 remark Allow SSH to staff or faculty vlan access-list 102 permit tcp 10.5.1.0 0.0.0.255 eq 22 any access-list 102 remark - access-list 102 remark Allow telnet to switches access-list 102 permit tcp 10.4.4.0 0.0.0.255 eq 23 any access-list 102 permit tcp 172.16.30.0 0.0.0.255 eq 23 any access-list 102 remark - access-list 102 remark Allow access to port 80 for servers access-list 102 permit tcp 192.168.36.0 0.0.0.255 eq 80 any access-list 102 permit tcp 10.4.2.0 0.0.0.255 eq 80 any access-list 102 permit tcp 10.4.3.0 0.0.0.255 eq 80 any access-list 102 remark - access-list 102 remark Allow access to port 443 for servers access-list 102 permit tcp 192.168.36.0 0.0.0.255 eq 443 any access-list 102 permit tcp 10.4.2.0 0.0.0.255 eq 443 any access-list 102 permit tcp 10.4.3.0 0.0.0.255 eq 443 any access-list 102 remark - access-list 102 remark Allow access to port 8080 for servers access-list 102 permit tcp 192.168.36.0 0.0.0.255 eq 8080 any access-list 102 permit tcp 10.4.3.0 0.0.0.255 eq 8080 any access-list 102 remark - access-list 102 remark Allow udp for DHCP, DNS etc.

There is very strict single subnet-mask limit on 2950 switches that require that all rules that belong to same access list use same kind of subnet masks.

But if we want to block ssh to all hosts then we block packets for destination port 22 and apply access list only on uplink port. Hence if we want to block ssh to particular host then we block packets that are coming from port 22 and apply access list on port on which host is connected. This is because we can apply access-list only to incoming packets on port and not to outgoing packets. If we want to block ssh to all nodes connected to this switch then we can use ' access-list 102 deny tcp any any eq 22' on uplink port.

The access list has to be applied on port on which host is connected and not on uplink port.

We can disable ssh to any host which is connected to specific switch port by applying below access list Note that subnet mask used in switch access-list configuration are opposite of normal netmasks configured in usual firewalls and interfacesĭisabling connections to/from hosts connected to specific ports Sample extended access-list configuration in which we have allowed only some specific IPs and some specific subnets to access switch.Īccess-list 100 permit ip host 10.1.67.15 anyĪccess-list 100 permit ip host 10.1.67.2 anyĪccess-list 100 permit ip host 10.3.3.51 anyĪccess-list 100 permit ip host 192.168.36.177 anyĪccess-list 100 permit ip 172.16.30.0 0.0.0.255 anyĪccess-list 100 permit ip 10.4.4.0 0.0.0.255 any Then we have to use extended access lists. In case access configuration based on networks, that is using subnet mask needs to be done then standard access lists are not enough.

To configure basic access control on switches (like Cisco 3750) we can create access list of IPs which are allowed to connect to switch and then apply that access list to vty lines. Home > Switch configuration notes > Configuring basic Access Control List (ACL) on Cisco switches Limiting access to vty lines based on source IP with access list