I86bi-linux-l2-adventerprisek9-15.2d.bin

If you get invalid memory access or a kernel panic, reduce the RAM to 192 MB or increase the bigphysarea to 20000 .

, though some users report occasional glitches requiring topology restarts. Simulation Efficiency: i86bi-linux-l2-adventerprisek9-15.2d.bin

| Problem | Likely Cause | Solution | | :--- | :--- | :--- | | | Missing bigphysarea kernel param | Add bigphysarea=10240 to QEMU command line. | | Console shows "No enough memory" | RAM allocation too high or too low | Set exactly 256 MB . Some OSs require 192 MB . | | Spanning-tree loops in GNS3 | Emulation CPU overcommit | Reduce number of switches or increase CPU cores allocated to QEMU. | | SSH fails with "No VTY" | Missing crypto key generation | Switch(config)# crypto key generate rsa modulus 1024 | | CDP neighbors missing | CDP disabled by default in some builds | Switch(config)# cdp run and Switch(config-if)# cdp enable | If you get invalid memory access or a

If the image starts but immediately stops, it’s almost always a missing or incorrect iourc file. | | Console shows "No enough memory" |