If you have a router in a modem+router combo, it's a fact that there is a firewall. This firewall has been there since the very first router. So fact, it has a firewall. Later they added more firewalls to block access from LAN to WiFi and such but item 2 is easy. It has one.
As to age, you didn't supply any details so you have to google make, model and look for date codes.
I just purchased a modem off of Ebay and I was just curious about 2 things.
1. Is there a way to find out how old the modem is? A manufacturing date or whatnot? The seller assured me the modem was less than a year old but I wanted to be sure.
2. Is there a way I can see if the Firewall is active? You an access the modem via the url 192.168.1.1. By doing this is there a way to check on a firewall status?

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