This is my specific context (Latex/TikZ code for the diagram below):Now this local Router, has broke down several times, and several different devices have had its role (sometimes they have a wireless interface too, sometimes not; currently, as on the image, they don't). The same goes for the Cable modem. However, regardless of such differences, I typically experience that:I can just wire this setup, and I get internet on the (Ubuntu GNU/Linux) PCs without any further tinkering with setupsThe local addresses of the PCs and the Router are always known (e.g. I can use tools like nmap to list the addresses of the local PCs and the local router). The global/Public IP is always known on the local PCs (through the use of whatismyip.com and such) The problem is the cable modem. I know it serves an administration page on port 80, because I've seen it before, when I had a different router. But, the thing is, I had forgotten what local IP is this cablemodem webpage supposed to be served on - I think with my previous local router, there was a page on its web interface which listed the cable modem local IP; I cannot find the same in the current router. So, the thing is - I want to access the administration page of the cable modem from PC1-3, but don't know what its local address should be; the other addresses are known as on the image. What tools (command-line or GUI) and approaches could I use, to find the cable modem's web server local IP address? Code for diagram:% drawn with tikzedt; to compile,% save as test.tex, and call: `pdflatex test.tex`\documentclass{standalone}\usepackage{tikz}\usetikzlibrary{shapes.symbols}\pagecolor{yellow!15}\begin{document}\begin{tikzpicture}\tikzstyle{rcn} = [draw,rectangle,inner sep=10pt,line width=1pt,align=center];\tikzstyle{ln} = [line width=1pt]\tikzstyle{cln} = [shape=cloud,draw,line width=1pt,fill=black!10,minimum width=10em,aspect=1.2]\tikzstyle{cln2} = [shape=cloud,cloud puffs=20,draw,line width=0.5pt,inner sep=0pt,align=center,aspect=3]\node[rcn] (PC1) at (1,4) {PC1\\Local IP: 10.0.0.2};\node[rcn] (PC2) at (1,2.5) {PC2\\Local IP: 10.0.0.3};\node[rcn] (PC3) at (1,1) {PC3\\Local IP :10.0.0.4};\node[rcn] (Router) at (6,2.5) {Router\\Local IP: 10.0.0.1\\\small(wired,LAN)};\node[rcn] (Modem) at (10.5,2.5) {Cable modem\\Local IP: ??.??.??.??\\\small(wired,wireless,router)};\node[cln] (Internet) at (15,2.5) {\Large Internet};\draw[ln] (PC1) -| (3.5,3) -| (Router.west);\draw[ln] (PC2) -| (Router.west);\draw[ln] (PC3) -| (3.5,2) -| (Router.west);\draw [ln](Router) -- (Modem) -- (Internet);\node [cln2] at (10.5121,4.7455) {Public IP (known):\\AAA.AAA.AAA.AAA};\end{tikzpicture}\end{document}
Tools to inspect local network, and find local IP address of device?
networking;utilities