09-14-2017 07:27 AM - edited 03-08-2019 12:02 PM
We have a ACL applied to the edge port to the internet to block malicous IPs. We also have login-block attempt configs. I will see logs on the router for let's say when I fail to login via ssh, but I was alerted by security they are seeing failed attempts and I confirmed they are via port 443. My question is basically the best way to block stuff like this. Should the ACL be applied to line vty lines? Is this why they are still making it to the router to try and enter creds?
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09-14-2017 09:48 AM
09-22-2017 06:13 AM
You could use a vpn or proxy server but at some level somewhere your public ip still needs to exist even if you mask it using features like that
https://www.lifewire.com/how-to-hide-your-public-ip-address-818380
09-25-2017 06:30 AM
09-26-2017 01:00 AM
I took a look at one of my edge facing devices and pulled some syntax that may help you definitly wont hurt to have it on your devices
the AAA i handcy of you ever go tacacs its the most secure in terms of router , then theres some config backups and source all mgmt traffic off 1 port where you can , and debugging seemed to get me what you were looking for try it out
service tcp-keepalives-in
service timestamps debug datetime msec show-timezone
service timestamps log datetime msec show-timezone
service password-encryption
no service dhcp
service sequence-numbers
security authentication failure rate 10 log
logging console critical
no ip http server
no ip http secure-server
no ip ftp username
no ip ftp password
ip ssh time-out 60
ip ssh authentication-retries 2
ip ssh source-interface x
ip ssh version 2
logging trap debugging
logging source-interface x
logging host x.x.x.x
ntp source x
kron occurrence SaveRunningConfigToStartupSched at 12:00 recurring
policy-list SaveMe
!
kron policy-list SaveMe
cli write
cli write
aaa group server tacacs+ ACSGROUP
server-private x.x.x.x key 7 151F4E36366F237D2A64637F404632483002187F7D
server-private x.x.x.x key 7 1214402D204E045D287C7275607406583642422678
ip vrf forwarding Mgmt-vrf
ip tacacs source-interface x
!
aaa authentication login default group ACSGROUP local enable
aaa authentication enable default group ACSGROUP enable
aaa authorization exec default group ACSGROUP local
aaa accounting exec default start-stop group ACSGROUP
aaa accounting commands 0 default start-stop group ACSGROUP
aaa accounting commands 1 default start-stop group ACSGROUP
aaa accounting commands 15 default start-stop group ACSGROUP
aaa accounting network default start-stop group ACSGROUP
aaa accounting connection default start-stop group ACSGROUP
aaa accounting system default start-stop group ACSGROUP
no ip bootp server
login block-for 300 attempts 10 within 60
login quiet-mode access-class X
archive
log config
hidekeys
path flash:Archive.cfg
maximum 2
write-memory
time-period 1440
!
When i set the logging to debugging and its applied to the wan facing internet i can tcp and udp outside requests being blocked by my acl in logs
Sep 26 06:36:32.105 UTC: %FMANFP-6-IPACCESSLOGP: SIP1: fman_fp_image: list 101 denied tcp 60.251.177.242(45014) -> 195.10.18.250(23), 1 packet
09-14-2017 07:41 AM
09-14-2017 08:43 AM
09-14-2017 08:46 AM
09-14-2017 09:15 AM
09-14-2017 09:48 AM
09-22-2017 05:39 AM
09-22-2017 05:59 AM
09-22-2017 06:13 AM
You could use a vpn or proxy server but at some level somewhere your public ip still needs to exist even if you mask it using features like that
https://www.lifewire.com/how-to-hide-your-public-ip-address-818380
09-22-2017 10:31 AM
09-22-2017 10:48 AM
09-23-2017 05:08 AM
Yes have strong acls , check show run all see what else is turned on by default turn off any services your not using , some routers have zbf too thats like a cisco ios fw , i dont use personally but you could look into it as an option or else use a small firewall in front of the router itself
https://www.cisco.com/c/en/us/support/docs/security/ios-firewall/98628-zone-design-guide.html
09-25-2017 05:38 AM
09-25-2017 06:30 AM
09-25-2017 09:29 AM
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