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Does a Cisco 2811 ISR Router allow any traffic to come in until an access-list is applied. &nbsp;The Reason I'm asking is, I have a 2811 that does not have an access-list on the outside (int fa0/0) and is allowing SMTP, HTTP, etc. &nbsp;I know on a Pix/ASA traffic will not come in the outside interface until an ACL is applied allowing it. &nbsp;
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Does a Cisco 2811 ISR Router allow any traffic to come in until an access-list is applied.  The Reason I'm asking is, I have a 2811 that does not have an access-list on the outside (int fa0/0) and is allowing SMTP, HTTP, etc.  I know on a Pix/ASA traffic will not come in the outside interface until an ACL is applied allowing it.  

Does a Cisco 2811 ISR Router allow any and all traffic to come in from the outside until an access-list is applied?

Hardware-based firewalls provide more sophisticated protection for inbound and outbound traffic than the simple Windows software firewall or the basic NAT firewalls found in routers. These devices implement techniques such as stateful packet inspection, deep packet inspection, and content filtering; and may include built-in antivirus and anti-malware protection.

Hardware Firewalls

A router is a networking device that forwards data packets between computer networks. Routers perform the "traffic directing" functions on the Internet. The most familiar type of routers are home and small office cable or DSL routers that simply pass data, such as web pages, email, IM, and videos between computers and the Internet. More sophisticated routers, such as enterprise routers, connect large business or ISP networks up to the powerful core routers that forward data at high speed along the optical fiber lines of the Internet backbone. Though routers are typically dedicated hardware devices, use of software-based routers has grown increasingly common.

Routers

A switch is a device that filters and forwards packets of data between LAN segments. Switches operate at the data link layer or the network layer of the Open Systems Interconnection (OSI) Reference Model and therefore support any packet protocol. LANs that use switches to join segments are called switched LANs or, in the case of Ethernet networks, switched Ethernet LANs. A hub is a connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports; when a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.