One of the jobs of a router is to connect networks that have physically different transmission media. Twisted-pair Ethernet is extremely common these days, but fiber (Ethernet, SONET/OC, and others) is used for most high-speed or long-distance runs, and different types of layer-2 and layer-1 networks have been used in the past and are still in use today, such as T1/T3 lines, ISDN, and Token Ring.
For historical reasons, serial cables such as HSSI may be used to connect equipment such as T1/T3 terminating devices. These will show up as interface SerialN, and you can get detailed information on the hardware installed in a router with show controllers serial.
Unfortunately, "DCE/DTE" technically applies to a number of different hardware signaling schemes. In the context of networking, it's most likely to refer to a serial interface that's used to connect to a WAN drop.
In the case of your simulator, you should practice with both types of interfaces. In most business networks, the "inside" interfaces will be Ethernet, while the WAN interface will be either serial or Ethernet depending on what service the telco is providing, and you'll need to be able to configure either one.
Answer from chrylis -cautiouslyoptimistic- on Stack ExchangeVideos
One of the jobs of a router is to connect networks that have physically different transmission media. Twisted-pair Ethernet is extremely common these days, but fiber (Ethernet, SONET/OC, and others) is used for most high-speed or long-distance runs, and different types of layer-2 and layer-1 networks have been used in the past and are still in use today, such as T1/T3 lines, ISDN, and Token Ring.
For historical reasons, serial cables such as HSSI may be used to connect equipment such as T1/T3 terminating devices. These will show up as interface SerialN, and you can get detailed information on the hardware installed in a router with show controllers serial.
Unfortunately, "DCE/DTE" technically applies to a number of different hardware signaling schemes. In the context of networking, it's most likely to refer to a serial interface that's used to connect to a WAN drop.
In the case of your simulator, you should practice with both types of interfaces. In most business networks, the "inside" interfaces will be Ethernet, while the WAN interface will be either serial or Ethernet depending on what service the telco is providing, and you'll need to be able to configure either one.
For the sake of completeness: Serial links are not solely used for gateway-WAN connections.
For instance, there are companies which host your network equipment and link your device via serial link to their infrastructure. Although your device is online with a public address, it still is not a DTE-like topology.
Another even more LAN-related serial link may be used on a daily basis by yourself and your colleagues: USB. Since USB does not only connect an end device to a storage device, but is also hosts to networks. An example for a host-to-LAN connection would be a tablet user currently being dislocated from a WAP. Because tablets usually do not have an Ethernet interface, a work-around is necessary. An example for a host-to-WAN connection would be field personnel accessing mobile broadband services via a pluggable antenna.
You might just be missing routing table entries.
- On Router0 you need to specify a route to 192.168.2.0/23 using 10.10.10.2 as gateway.
- On Router1 you need to specify a route to 192.168.0.0/23 using 10.10.10.1 as gateway.
Make sure all routes are configured on each device in their areas. Set up OSPF routes and make sure both routers have them. And make sure both routers can ping each other as well. Routing tables in both routers have to reflect the other network for this to work add a default route.