Assuming TFTP server at 192.168.1.100, router IP 192.168.1.1:
Surprisingly, "better" code sometimes removes deprecated features. If you rely on or L2TP (non-IPsec) , this image deletes support. Similarly, some third-party DSL chipsets on the 800 series behave poorly with the 15.9 train compared to the 15.4 train. c800universalk9mzspa1593m10bin better