C3900-universalk9-mz.spa.157-3.m8.bin May 2026

ip access-list standard MANAGEMENT-PERMIT permit 10.0.0.0 0.255.255.255 deny any log

No new security patches were issued after Cisco end-of-life for ISR G2 (announced 2020/2021). Using this in a current internet-facing role is not advisable without lockdown (no management from WAN, ACLs, COPP). C3900-universalk9-mz.spa.157-3.m8.bin

: Designates that the file is digitally signed by Cisco, ensuring the integrity and authenticity of the software. ip access-list standard MANAGEMENT-PERMIT permit 10