05-15-2020 02:23 PM
I am a very new at protecting a Cisco router from Internet attacks when they have a dedicated IP address. I tried the AutoSecure command, but it shut everything down even though I went through the question process with it. Security is not my area of specialty. I am more of a CME person.
I am the vendor and we have a customer that we have a DMVPN connection to on an as needed basis. Most of the time, the VPN is down. But, when they need changes made on their router (mostly CME things), they enable the tunnel via a web page that I wrote. Since both our edge router and theirs have a public IP address, I need to configure some good security. There are no firewalls at either site beyond what Windows has built in. That Is a rabbit hold I don’t want to jump down just yet.
Both HA Q and Customer A are live on the Internet now and running companies so when I apply an access-list or any other command, I need to be sure to not cause interruption in their services or lose access to them via the VPN tunnel as the customer location is 35 miles away; it will be difficult to just restart the router.
Please see my topology below and make your recommendations as per my needs listed:
The HQ location has a DMVPN tunnel to the Customer A router on the 172.16.1.0/16 network and we must be able to telnet from the HQ A router to the Customer A and Customer B routers through the tunnel ONLY.
The HQ location has another VPN between HQ and a Home location on the 172.31.0.0 network.
The customer also has a VPN on the 172.20.0.0 network.
Both of these tunnels stay up permanently and are completely separate from the HQ to Customer VPN.
We login into the HQ A router then telnet to the Customer A router. If access is needed to the Customer B router, we must first connect to the Customer A router then telnet from the Customer A router to the Customer B router.
Below is a list of services that I shut down, a vty protection access-list, and a sample access-list for protecting the Internet connection. What changes/deletions/additions do you suggest?
DISABLED SERVICES
no snmp-server
no service finger
no ip source-route
no ip proxy-arp
no ip directed-broadcast
no service tcp-small-servers
no service udp-small-servers
VTY PROTECTION
access-list 50 remark VTY_ACCESS_CONTROL
access-list 50 permit 192.168.0.0 0.0.255.255
access-list 50 permit 172.16.0.1 0.0.0.0
access-list 50 deny any
line vty 0 4
access-class 50 in
line vty 5 15
access-class 50 in
INTERNET PROTECTION
int g0/0
ip access-group Protect in
no ip redirec
no ip mroute-cache
exit
ip access-list extended Protect
remark Protect connections from Internet access and attacks
permit tcp any any eq smtp
permit tcp any any eq pop3
permit tcp any any eq domain
permit tcp any eq domain any
deny tcp any any eq ftp-data
deny tcp any any eq telnet
permit udp any any eq domain
permit udp any eq domain any
deny udp any any eq snmp
deny ip host 0.0.0.0 any
deny ip 127.0.0.0 0.255.255.255 any
deny ip 192.168.0.0 0.0.0.255 any
deny ip 172.16.0.0 0.0.255.255 any
deny ip 10.0.0.0 0.255.255.255 any
deny ip 224.0.0.0 31.255.255.255 any
deny icmp any any redirect
permit ip any any
Do I need to add the following for access to HQ A router FTP server which does have port 80 web services?
permit tcp any host 192.168.69.61 eq www
permit tcp any host 192.168.69.61 eq 443
permit tcp any host 192.168.69.61 eq ftp
permit tcp any host 192.168.69.61 gt 1023
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide