Questions tagged [acl]
Discussion on Access-Control-Lists (ACL) or Access-Control-Entries (ACE)
215
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Inherent flaw in stateless firewalls?
I am but a lowly (software) developer dabbling with setting up a network in AWS and am having trouble understanding the fundamentals of stateless firewalls, or Network ACLs as they're also referred to ...
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0
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30
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TACACS Through ASA L2L Tunnel
Hello see below network diagram.
I am trying to configure the Branch Router (10.1.1.1) to use TACACS AAA on the HQ-AAA-Server host (192.168.10.10). TACACS works fine for the Branch-FW1 ASA device ...
- 121
0
votes
1
answer
162
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Access TACACS+ Server through ASA
I am trying to set up TACACS+ for a project. The below image shows the layout of the network.
So far I have the TACACS+ server set up and working (HQ_AAA_SERVER) and it works fine for authentication ...
- 121
1
vote
1
answer
93
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Cisco ASA Clientless SSL VPN Restrict Network Access
I'm working on a Uni project to set up a secure network. One aspect is to have a VPN for clients of the imaginary company to access web based services.
I have set up a simple clientless SSL VPN which ...
- 121
0
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1
answer
105
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Configure AAA on a router - Extended ACLs
How do I write a named extended ACL which will allow for traffic between a DNS from a LAN (IP address) to a DNS server at (IP address), ping from a host PC (IP address) to any destination and allow ...
1
vote
1
answer
47
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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 ...
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4
votes
1
answer
226
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Correct ACL rules to isolate WiFi traffic from other VLANs?
I have written ACL rules written for a Dell PowerConnect 8024F (which, for the most part, uses the Cisco ACL "language") to isolate WiFi traffic from the rest of the network but allow the ...
- 143
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1
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85
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Cisco ASA access-lists and net config
Here are my config to this network. I found the ASA doesn’t ping through each other. Also, when I type show crypto isakmp SA and IPSec Sa, it doesn’t show anything at all. Could you guys find what’s ...
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2
answers
39
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Cisco MAC ACL loop holes
I know this is not a new topic but need to clarify a couple things.
I have a typical office with hosts connected to a Cisco 3560-X in same VLAN.
My goal is to prevent unauthorised hosts ever accessing ...
1
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0
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27
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ACL dont work - MASTER VLAN to see ALL OTHERS BUT NOT VICE VERSA [closed]
I am having a bunch of VLANS that are in our HQ. Idea is that only several subnet must see IT department VLAN and all others DONT but IT department must see all vlans.
I tried like this, to make all ...
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1
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453
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How do I apply an access list on a switch?
I'm configuring a very small network on packet tracer 8.0 and I have a single 2960-24TT switch which is connected to 2 PCs and 1 router. Everything is on the 24.17.2.0/24 network and I added a VLAN. I ...
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3
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1
answer
246
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Cisco ACL numbering
This is a small technical question. I can't seem to find any information on this, so I thought I'd ask here.
I'm currently studying for my CCNA and I'm currently on the topic of ACLs. On IOS standard ...
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1
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182
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How to block telnet access for one particular network from all networks except one using Extended ACL
Scenerio is given in the picture. I want to block all the networks except 192.168.5.128/25 from doing telnet of 192.168.5.0/25.
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Access-class in denies telnet under specific configuration
So I created an Access-list to permit telnet from a specific subnet. Here is the network diagram.
I originally tried permitting the subnet 10.1.1.0 /24 to access the R4 vty lines 0 4. It was a ...
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74
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Allow one way SSH on extended IP access list on Cisco switch
interface GigabitEthernet1/0/11
ip access-group VM01-BLOCK-SSH-ACCESS-OUT out
objective:
10.10.10.104 -x-> any 10.10.10.0/24 via SSH
any 10.10.10.0/24 via SSH ---> 10.10.10.104
Question: ...
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1
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219
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Cisco L2 switch port ACL options
I'm trying to understand Cisco Switch ACL options I can potentially use to limit traffic. Switch is a IE2000 series with Lanbase IOS. It is L2, with trunk port to uplink switches, multiple VLANs on ...
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1
answer
221
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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....
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1
vote
1
answer
181
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VLAN Filtering not working
On Cisco devices I'm looking to enable some filtering for one specific vlan (id 110).
Here is my config : (192.33.57.177 is the DHCP server host)
ip access-list extended VLAN110-DHCP
permit ip any ...
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1
answer
109
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Blocking 2 VLANs from accessing a specific VLAN on a network
I'm working on a project in packet tracer and I have a server connected to VLAN 10.
VLAN 10 has a single server device on it and the IP scope is a /30.
I have 8 other VLANs across 2 sites. The 2 ...
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0
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2
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57
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meaning of acl configurations?
how do we know what ACL configuration mean? an example access-list 89 permit tcp host 192.168.10.2 any eq www? does this allow the traffic from the host 192.168.10.2 inside? i'm a bit confused. any ...
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2
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184
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When do ACLs on SVIs get applied on Cisco Catalyst devices?
I don't understand exactly when an ACL will get applied when on an SVI. Given the following (pseudo) configuration
int vlan 100
ip address 10.0.0.1 255.255.255.0
ip access-list in in
ip access-...
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0
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229
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Juniper MX Routing Engine Firewall Filter
I'm having difficulties with something I initially thought would be rather simple. I need to apply an outbound firewall filter on an MX10003's management interface. I'm currently using Lo0.0 as the ...
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3
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257
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Egress filtering by blocking unused ports
Our company wants to block data exfiltration. They want to control outbound traffic going out from unused ports. I did traffic flow analysis at our edge firewalls to know which ports are used by our ...
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2
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2k
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Permit ping and traceroute and deny all other services using an ACL
my topology is shown below:
I would like the networks that are connected to Hermes-Router to be accessible from all the other stations only when I use ping and traceroute. I tried to do this using an ...
2
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0
answers
42
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How to configure an ACL on ASA when the inside source IP address is translated by NAT? [closed]
I don't know how to configure an ACL when inside source nat is enabled.
In my example, I want to realize bidirectional communication with TCP port 30000 between 172.16.100.100(inside) and 10.10.10.10(...
1
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1
answer
882
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DNS expire-entry-timer has negative affect on ASA using FQDN ACL
I have a Cisco ASA using FQDN egress ACLs for a host that changes IP addresses every 10 mins (Apple APNS IP address pool). As soon as the TTL expires for the addresses, my internal server requests a ...
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4
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1
answer
2k
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Cisco Nexus 9300 TCAM carving
I have Cisco Nexus C9396PX L3 switch and i have configured bunch of ACL (inbound) on it to deny/permit traffic. now if i am trying to add more ACL then getting error that your TCAM table is full. here ...
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2
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2
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Restricting TFTP access from Host to Router using extended ACL in Cisco IOS
I am trying the below Extended ACLs to restrict TFTP but still I am able to upload files to the router using tftp. Not sure, what is wrong, can you all help?
Approach 1:
permit udp host <ip> ...
- 51
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4
answers
651
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ACL on routers to block TCP/UDP ports
How routers understand the layer 4 port numbers to be blocked in ACL?
When an ACL to block TCP/UDP traffic with certain port numbers is applied on a router/L3 interface , how will router understand ...
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1
answer
181
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N2K-C2248TP-1GE question
We are working with Cisco 2960 and Cisco 4948 switches as our top of rack switches and we want to purchase some N2K-C2248TP-1GE , and connect N2K-C2248TP-1GE to our edge switches, (our edge switches ...
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1
answer
633
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delete object network in cisco ASA with packet tracert
I used 5506 as firewall and I am trying to delete object network I created and it gives error as ERROR: unable to delete the object configuration. object (inside-net-obj) is being used.
commands I ...
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2
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1
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configure IPv6 ACL on interface WS-C3750X-48
I am using WS-C3750X-48 model switch. license is lanbase. I have activated cmd on my switch:
sdm prefer dual-ipv4-and-ipv6 routing. Then i did reload. After that, i will able to config IPv6 on ...
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1
answer
53
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Router Standard ACL
I was configuring Standard ACL on router 1841 on Cisco Packet Tracer with the help of command access-list 1 permit 172.16.40.3 0.0.0.0 and access-list 1 deny 172.16.40.4 0.0.0.0 and then I applied ...
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2
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Nat ACL Question?
I am so confused with fundamentals that I used to be an expert in,
so I have this topology
Please answer to my questions separately,
Question 1) So if I have two DNS severs, and ofc two IP address(81....
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3
votes
1
answer
182
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Access control on Cisco router with switchports?
I am working with a series 800 router which has inbuilt switchports.
I want to use 2 switchports for a VLAN (say VLAN 100).
On one port will have devices:
192.168.1.10
192.168.1.30
Connected to ...
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1
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484
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how to send tcp packets between 2 hosts on same network
iam using mininet network simulation tool and i need to send tcp packets between 2 host hosts are 10.0.0.1,10.0.0.2 ,i used the hping3 but is sends ip packets also i used this command
hping3 -c 1 [...
3
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3
answers
968
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How to add multiple ip address in destination ip in acl rule
Iam trying to block a certain host from sending any message to any host in the network
is there is a way to do that or i have to deny host by host ?
2
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1
answer
103
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Using Extended ACL on destination instead of source
In the diagram we are required to block all the external user ping requests to the sever. For this I have created the following ACL on R1:
access-list 105 deny icmp any any echo
access-list 105 ...
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2
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1
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47
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What interface would ACLs be under if two services were connected over a S-2-S VPN?
I am using the ADSM for ASA tool.
I am trying to connect a service to a mysql server using port 3306. The service runs on a server that is on another network to the mysql server. It has been ...
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3
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366
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Using Standard or Extended ACL for Telnet Connections
In the picture shown the left bottom router is to be secured from any telnet requests. Now will I use Extended ACL on every router router or can I use the standard ACL just?
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3
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ACL for DNS clarification
I do not understand why the second ACL is needed if all I want is to ensure all networks use a certain DNS server (for example 192.0.2.1)
access-list 112 permit udp any host 192.0.2.1 eq domain
...
0
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1
answer
119
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How do I apply ACL in the given topology?
I am trying to understand the concept of standard and extended ACL. In the given topology, the top router is Front Desk(192.168.11.0/24). The left router is Nurses (192.168.7.0/24), left bottom is ...
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1
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How to group 3 hosts in ACE Ipv6 statement
I know for ipv6 ACE there is no wildcard mask, so if I want to add three hosts in one statement, for example, which prefix should I use for that network? (network 2001:db8:cafe:1/64, ::1 reserved as ...
1
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1
answer
211
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ACL not blocking IP or ICMP packets out of an interface
I created this network to do some general practice. Every host on the network can ping every other host. The routers are just using a basic RIPv2 configuration. All of the interfaces can ping all the ...
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1
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250
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Create ACL for VLAN
I've multiple switches in LAN network environment configured with 3 VLANs, namely VLAN A, VLAN B and VLAN C. Since VLAN A is only allow to access internet without having accessibility to internal ...
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1
answer
535
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What can I use to block all the ports of the WAN in a Cisco router?
I have set up my small network using Cisco ISR C1111-8p and a Cisco Wireless AP C1832i.
What can I use to block all the ports of the WAN?
Is there any security advantage blocking them rather than ...
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1
answer
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Why does the Implicit Rule prevent traffic from passing?
I an testing traffic forwarding between different DMZ with different security levels.
DMZ:
interface GigabitEthernet0/1.351
vlan 351
nameif dmz
security-level 10
ip address 10.100.20.1 255.255....
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2
answers
853
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Providing wildcard mask in extended ACL
Is it necessary to provide a wildcard mask in extended ACL?
For example, if I want to block 192.168.5.2 from gaining access to 192.168.7.2, can I write the command as follows?
access-list 107 deny ...
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1
answer
67
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source and destination in access-list
I am a bit confused in the concept of source and destination. Consider that I have to create an extended acl which blocks the access of 192.16.3.0/24 from 192.16.7.0/24. In this case my source is 192....
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1
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53
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Permit only WEB server in ACL on router? [closed]
In that topology I need to configure
192.168.1.0/24 will block 10.10.20.20 host
192.168.2.0/24 will block 10.10.10.0/24 network
All users can view web page but can't ping etc ...
I done that top 2 ...
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