All Questions
33 questions
1
vote
1
answer
141
views
What's the procedure to limit a subnet on a Cisco router from seeing another subnet when both are using NAT?
I have a Cisco 891F router. The internet is hooked up to G8. The student network is Vlan 200, and the Office is Vlan 100.
(I know the internet has an internal subnet (192.168.1.5), but that's because ...
- 113
1
vote
1
answer
494
views
Access list command for specific IP range in Cisco Router 1921
For example:
router(config)#ip access-list extended 101
router(config-ext-nacl)#10 per icmp any host 192.168.1.10
From second command line, how to write a command permit icmp any host range 192.168.1....
- 11
3
votes
1
answer
2k
views
L3 and L2 interfaces in ACL
What is L3 and L2 interfaces in ACL feature
and why ethernet access-lists will not support L3 interfaces
- 31
2
votes
2
answers
5k
views
Is "Host unreachable" the same as "Communication administratively prohibited" in Access List ping response?
Below is a portion of my topology.
Faculty of Arts student subnet should not be able to ping Faculty of Arts staff subnet but the staff should be able to ping the student subnet. I know that this ...
- 69
2
votes
1
answer
22k
views
how to deny ping from one direction but not the other using Access-list
Hello everyone.
What I'm trying to do is to deny ping access from the 12.12.12.0 network to reach the 10.10.10.0 network but not deny ping access to go from 10.10.10.0 network and reach the 12.12.12....
- 23
1
vote
1
answer
56
views
Help with this acl
This is what i am trying to do
Deny the network that host 200.200.200.10 is on, telnet access to R3
Permit host 200.200.200.10 to telnet to R3
Deny host 200.200.200.10 all access to host 204.10 on ...
- 13
2
votes
3
answers
1k
views
Understanding Cisco standard access lists (Packet Tracer example)
Consider the following example: I have two networks (192.168.1.0 and 192.168.2.0) with one PC in each network (PC0 - 192.168.1.1 and PC1 - 192.168.2.1) and a router R0 with 2 interfaces connecting ...
- 23
1
vote
1
answer
434
views
Cisco Router, Port Forwarding, ACL ordering
I'm new CCNA learner here.
If I have the following access list:
access-list 101 permit ip 10.10.0.0 0.0.255.255 any
access-list 101 deny tcp host 10.10.0.1 eq 443 any
access-list 101 deny tcp host ...
- 61
1
vote
3
answers
945
views
Access Control List in Firewall and Router
1)
Why do we need to specifically deny ip xxxxx xxxxxxx, when at the end of every ACL statement, WHEN there is a default "deny any any" statement?
Meaning we just permit only what we need and let ...
- 11
1
vote
2
answers
4k
views
Cisco ACL- How to block the public from internal access while allowing an internal system to use public web?
I am having trouble with allowing my internal system (Administration) public web access after denying any of the public access to my internal systems.
Here is my ACL on my router so far:
Extended ...
- 31
2
votes
1
answer
34k
views
Deleting Access Control List in Cisco Router
Let's say I have a access-list 1 with 5 permits.
And I would like to delete the third permit listing.
I know that I can simply do "no 30"
However, can I confirm that I can
no access-list 1 permit ...
- 83
2
votes
1
answer
1k
views
How to prevent IOS sending icmp unreachable with output ACL?
I have an output ACL applied on a WAN interface that permits only 1 IP from going out.
interface Cellular0
ip address negotiate
ip access-group allow100.98.170.25 out
ip nat outside
no ip ...
- 252
1
vote
4
answers
721
views
Cisco IOS - dropping all traffic not translated by NAT
I have a couple of rather basic questions about NAT translation.
For a simple translation like:
ip nat inside source list ACL interface GigabitEthernet 0 overload
If the traffic does not match ACL, ...
- 252
1
vote
1
answer
3k
views
Why is my ACL not blocking traffic on my cisco router interface?
So here is my config.
I want traffic coming from all networks except 172.23.1.0/24 to be blocked by inferface fa 0/0
So on the router I creater 2 ACLs
ACL 10
R1# access-list 10 permit 172.23.1.0 0....
- 190
1
vote
1
answer
194
views
Will Cisco IOS routers pass all traffic by default without ACLs?
I have a 1941 out of the box. I can't find documentation on this anywhere, but I'm wondering if the router will pass all traffic by default without adding any ACLs?
I'm curious if the implicit deny ...
- 491
1
vote
1
answer
65
views
ACL does not work properly
I have a 200.1.1.0/24 network and a web server which is 150.1.1.100. I want to apply an extended ACL to allow devices in network 200.1.1.0/24 with IPs in the range 1-127 to communicate with the WEB ...
2
votes
2
answers
209
views
ACL on virtual interface get ignored
Good evening!
Recently i've got some problem in configuring cisco router (IOS 12.x). There is an virtual interface for a vlan:
interface GigabitEthernet0/1.203
description Department XXX
...
- 131
2
votes
2
answers
2k
views
ACL on Internet Facing Interface
I have to set up and design a network as illustrated in:
I need to configure ACLs on inside interface and outside one. However, when
I implemented the access-lists, the flow of traffic was affected ...
- 21
0
votes
1
answer
548
views
Extended access list conflict condition will it cause override?
Corp1(config)# access-list 10 permit tcp 192.168.33.3 0.0.0.0 177.22.242.23 0.0.0.0 eq www
Corp1(config)# access-list 10 deny tcp 192.168.33.0 0.0.0.255 177.22.242.23 0.0.0.0 eq www
Corp1(config)# ...
- 111
1
vote
1
answer
224
views
I can't ping denied network
I have created an access-list on my router.
I denied one network, then permitted any.
Denied network cannot ping my network. It is OK.
But I also cannot ping that network. Why?
Who can explain me?
...
- 144
1
vote
1
answer
55
views
How do i set this ACL on the router
I was told in a previous answer to use
ip access-list extended TEST
deny ip host <PC0 address> host <PC5 address>
permit ip any any
But, whats the command to set it on the router ...
- 63
2
votes
2
answers
193
views
Simple ACL question
I'm still new to networking and have a question or problem I need to solve, but I'm not sure how to move forward. I need to stop PC0 from Vlan10 from talking to PC5 in Vlan30, but he must be able to ...
- 63
2
votes
2
answers
4k
views
Cisco router - deny access to host on port 8080, allow on 80
I'm designing a network with the following scheme:
I have 5 vlans, 3 on S1 and 2 on S3. I'm currently concerned with making access list. Each vlan has a web server that is configured to listen on ...
- 123
2
votes
1
answer
7k
views
Access list policy with odd and even filtering
I'm having some issues with some access list configuration regarding a topology. The lab requirements are:
Deny any host with even-numbered IP addresses from the BM_R1 LAN from
accessing hosts on the ...
- 23
2
votes
1
answer
744
views
Cisco ACL not working as expected
I've a client to which I want to deny access so that he cannot access my network host. There is this specified port that he scanned on my network host which I want to block (Port 137).
Using NMAP, ...
- 21
2
votes
1
answer
10k
views
Block Inter-Subnet Routing -Ubiquiti Edge Router
I would like to know how to block routing between subnets on my Ubiquiti EdgeRouter. These subnets are on 6 different VLANs, and the layout goes like this:
VLAN 1 - 10.0.0.1/24 (management)
VLAN ...
- 108
4
votes
1
answer
719
views
Block port with single exception on Cisco 803
This seems fairly straight forward, though I'm having trouble finding a solution on Google and in the Cisco documentation. I think I'm perhaps just not looking for the correct thing.
Essentially I ...
- 175
7
votes
3
answers
7k
views
Edit Cisco IOS ACL without hanging the router
I have a Cisco Router 1941 Series and I want to make some changes to the access-list on the router. I got to know I will have to delete one of the list and then re-add everything again with my ...
- 569
6
votes
2
answers
6k
views
Change Ping Response for Traffic Blocked by Access Control List
I am trying to ping a host, let's say 10.1.1.1, from 20.1.1.1.
I have created the ACL:
R1(config)#access-list 1
R1(config)#Deny 20.1.1.1
R1(config)#Permit any
R1(config)# int s0/0
R1(config-if)#ip ...
- 153
4
votes
2
answers
836
views
The Difference Between ACL and FPM
What's the difference between ACL and FPM? In detail, please, but in a simple, easy-to-understand way.
- 43
14
votes
2
answers
2k
views
BGP regular expression .+_.+_.+_.+_.+_.+_.+_.+_.+_.+_.+_.+
could anyone tell me what ip as-path access-list 100 deny .+_.+_.+_.+_.+_.+_.+_.+_.+_.+_.+_.+ stands for?!
I searched over the internet for the meaning of this regular expression, but I was unable to ...
- 275
18
votes
7
answers
68k
views
Cisco command to show which interfaces an ACL is applied to
For Cisco routers and switches, is there a show command, or something similar, that will display what physical and logical interfaces an ACL is implemented on and what direction it is applied in?
I ...
- 3,129
7
votes
2
answers
4k
views
How to configure OOB access via IP
Single Cisco IOS device in a remote DC, I have an OOB connection delivered into the rack (length of Cat5e into my rack from another onsite providers rack, who have diverse routes from my own, in and ...
- 5,310