Understanding Neighborcast - F-Secure Community

header {margin:52px 0 0 0} #dropdownnavi {float:left; clear:both; margin: -2px 0 20px -12px;} header .row {width:100%} header .row:nth-child(1) {background-color:#0014a0} header .container, footer .container {max-width:1172px; margin: auto;} .top-header {height:53px;} .bottom-header {height:52px;} .Header-logo {width: 10%;float: left;} .Header-logo img {width: 105px; margin: 11px 8px 8px 16px;} .header-top-links {float: right; margin: 1px 29px 0 0;} .header-top-link, .header-bottom-item {cursor: pointer; display: inline-block; font-size: 14px; font-weight: 400; line-height: 52px; margin: 0 15px; position: relative; text-align: center; } .header-top-link, .header-bottom-item a {text-decoration:none;} .header-top-link {color: #fff; margin: 0 10px 0 12px;} .header-top-link.active {margin-right:12px} .header-top-link.active::after {width: calc(100% + 30px)!important} .header-top-link.active::after, .header-top-link:hover::after {background: #fff;} .header-bottom-link {color: #1e1e1e;} .header-bottom-item .header-bottom-link {margin:0 15px} #homeLink {margin-left:1px} .kb-lang-title {width:100%;text-align:center;font-weight:600;color:black; margin:0} .header-right {float: right; margin: 10px 48px 0 0; padding: 3px; height: 30px; border-radius: 3px;} #signin {margin-top:5px} #signin a {text-decoration: none; color:#1e1e1e; } .signin-icon {float: left; height: 20px; padding: 0 5px 20px 0;} #profiledropdown {padding: 2px; border-radius: 3px; margin-top: -3px;} #profiledropdown:hover {cursor:pointer; background-color:#0014a0} #profilename #profileicon {background: #dfdfdf; border-radius: 25px; width: 28px; height: 28px;} #profile-menu ul {list-style: none; padding-left:0} #profile-menu ul li {padding:10px 0 10px 20px;font-size: 15px;} #profile-menu ul li:hover, #articleslink p:hover, #dashboardlink p:hover {cursor:pointer; background-color:#efefef;} #profile-menu ul li a {text-decoration:none; color:#1e1e1e} #profile-menu hr {border:1px solid #efefef} #articleslink hr, #dashboardlink hr {margin:0} #articleslink .title {padding: 0;text-align: center; font-weight: 600;} #articleslink p, #dashboardlink p {padding:10px 0 10px 20px;} #articleslink p a, #dashboardlink p a {text-decoration: none; color:#1e1e1e;} #articleslink .draftslink:hover, #dashboardlink p:hover {padding: 10px 0 10px 20px;} .header-coveosearch {position: relative; margin-top: -53px;} .header-search {display:inline-block;padding:15px 0 0 0;} .searchboxtoggle {color:white;} .header-searchcontainer {float: right; margin:0 18px 0 0; height:52px} .search-icon {color:white;} .expand {display:inline-block;} .collapse {display:none;} .searchboxtoggle .opensearch-icon, .searchboxtoggle .closesearch-icon {cursor:pointer;height:26px; width:26px; vertical-align: middle; filter:invert(1)} .header-searchbox {height:52px;} #kbsearch {display:block;margin: 0 0 0 auto; height:53px; box-sizing: border-box; border: 1px solid white; font-size: 14px; padding: 14px 0 10px 15px;} header-searchbox.active, #kbsearch:focus {width: 100%; transition: 1s ease-in-out;} .Footer {background:#f6f6f6;color:#555a62;font-size:16px;line-height:1.5;padding:18px 0; border-top:1px solid #c4c4c4} .Footer .footer-logo-wrap .footer-logo {height: auto; max-height: 32px; width: auto; margin-top:20px} .Footer .col {padding:0 0 0 15px;width: 20%; font-size: 13px; display: table-cell; vertical-align: top;} .Footer .footer-links-wrap {padding-bottom: 15px; border-bottom: 1px solid #c4c4c4;} .Footer .footer-links-wrap .col:nth-child(2), .Footer .footer-links-wrap .col:nth-child(3), .Footer .footer-links-wrap .col:nth-child(4) {border-right:1px solid #c4c4c4} .Footer .col ul {list-style: none;} .Footer .col:nth-child(2) ul {padding: 0;} .Footer .col ul li a {color: #1e1e1e; text-decoration: none;} .footer-link-title {text-transform: uppercase; color: #1e1e1e;} .footer-link-subtitle {font-size:14px; color: #1e1e1e; max-width:95%} .footer-icon {float: left; height: 30px; padding: 0 10px 60px 0;} .col-copyRight a, .social-icons-wrap a {display:inline-block; padding:5px 0; text-decoration: none; color: #1e1e1e; } .social-icons-wrap {float:right} .Footer a:hover, .Footer .col ul li a:hover {color:#0014a0} footer.Footer .row.bottom-row {padding-top:5px} footer.Footer .row.bottom-row .col.col-copyRight * {font-weight:400} social-link:hover {cursor:pointer} social-link:hover svg {fill:#0014a0} #signin .header-bottom-item.header-bottom-link {display:inline-block; margin-top: -16px;} #signin a:hover {color:#0014a0} @media screen and (max-width:991px){ header {margin:0} header .row:nth-child(1) {height:64px} .Header-logo img {margin: 17px 8px 8px 16px;} .Hamburger-border {position: absolute; right: 60px; border-left: 1px solid #fff; height: 64px; width: 50px; top: 0; z-index: 20; border-right: 1px solid white; padding-right: 10px;} .Hamburger {display:block;position: absolute; top: 8px; left: calc(100% - 52px); z-index: 20;-webkit-box-align: center; -webkit-box-pack: center;-webkit-user-select: none; align-items: center; background: transparent; border: none; border-radius: 0;cursor: pointer;justify-content: center; outline: none;transition: .35s;} .Hamburger-menuXcross {height: 25px; padding: 0; width: 26px;} .Hamburger-menuLines {-o-transition: .35s;-webkit-transition: .35s; background-color: #fff; border-radius: 2px; display: inline-block; height: 2px; position: relative; transition: .35s; width: 26px;} .Hamburger-menuLines::before {top: 6px; } .Hamburger-menuLines::after {top: -6px;} .Hamburger-menuLines::after, .Hamburger-menuLines::before {-ms-transform-origin: 5.5px center;-o-transition: .35s;-webkit-transform-origin: 5.5px center;-webkit-transition: .35s;background-color: #fff;border-radius: 2px; content: ""; display: inline-block; height: 2px;left: 0;position: absolute;transform-origin: 5.5px center;transition: .35s;width: 26px;} .sr-only {position: absolute !important;width: 1px !important;height: 1px !important;padding: 0 !important;margin: -1px !important;overflow: hidden !important;clip: rect(0,0,0,0) !important;border: 0 !important;} .Hamburger-menuXcross.isToggled .Hamburger-menuLines::before {-webkit-transform: rotate(45deg); transform: rotate(45deg);} .Hamburger-menuXcross.isToggled .Hamburger-menuLines::after {-webkit-transform: rotate(-45deg);transform: rotate(-45deg);} .Hamburger-menuXcross.isToggled .Hamburger-menuLines::after, .Hamburger-menuXcross.isToggled .Hamburger-menuLines::before {-ms-transform-origin: 50% 50%;-webkit-transform-origin: 50% 50%;background-color: hsla(0,0%,100%,.6); left: 0;top: 0;transform-origin: 50% 50%;width: 26px;} .Hamburger-menuXcross.isToggled .Hamburger-menuLines {background: transparent;} .isToggled .Hamburger-menuLines {-webkit-transform: scaleX(1);transform: scaleX(1);} #signin {text-align:center; margin: auto; color:white} #signin a {text-decoration: none; color:white;} .header-top-links, .bottom-header {display: none} .header-coveosearch {margin-top:0} .header-searchcontainer {color: white; text-align: right; margin: 8px 18px 0 0;} .header-search { padding: 11px 0 0 0; width: 60px; margin: auto; display: block; position: absolute; right: 17px; top: 8px;} .searchboxtoggle {color:white} .header-searchbox {position: absolute; right: 60px; top: 0; width: 300px;} #kbsearch {height:66px} .banner-middleContainer_f1l0wf96 {box-shadow: inset 0 10px 10px -10px #000;} #homeLink, #helpForumsLink, #FaqsLink, #userguidesLink, #supportLink, .header-right {width:100%; text-align: left; margin: 0; } #userguidesLink, #supportLink {border-top: 1px solid #dfdfdf;} #helpForumsLink, #FaqsLink {margin: 0 0 10px 25px;} .top-header-link {text-transform: uppercase; font-weight:700; color:#1e1e1e; font-size:14px; padding:15px 15px; line-height: 2em;} #dropdownnavi .top-header-link {margin: 3px 0 0 10px;} .header-bottom-link::after {background:none;} .header-bottom-item .header-bottom-link {margin:0 10px} .depth-1-list, .depth-2-list, .depth-3-list {list-style: none; margin: 0; padding:0 0 0 40px} .kb-lang-title {text-align:left;} #menu-dropdown {margin-top: -20px;} #kb-menu-dropdown .depth-2-list.open {padding-left:30px} .depth-1-list a, .depth-2-list a, .depth-3-list a {color:#1e1e1e} .smdropdown-alt {line-height: 0; margin:0 padding: 0 0 10px 0;} .smdropdown-link {color:#acacac!important; font-style: italic;} .depth-1-list, .depth-2-list, .depth-3-list {display: none; margin: -20px 0 20px 0; padding: 0 0 0 15px;} .header-right {float: right;padding: 8px 0; height: 30px; border-radius: 0; box-shadow: 0 3px 5px #1e1e1e; background:#0014a0; text-align: right;} #profiledropdown {width: 30px; float: right; margin-right: 40px} #profiledropdown:hover {background: none} #profiledropdown:hover #profile-menu {display: none} #profileicon {margin-top:2px} #profile-menu {display: none; position: absolute; left: 5%; background: white; width: 90%; text-align: left; z-index: 400; border: 1px solid #dfdfdf; border-radius: 3px; box-shadow: 0 5px 5px #dedede;} .open {display: block;} .Footer .col {display: block; width:90%; padding: 0 20px 15px 20px} .Footer .col.col-copyRight, .Footer .col.col-social {width:90%} footer .container {width:95%} .col.footer-logo-wrap {text-align: center;} .col-copyRight a, .social-icons-wrap a {padding: 10px 0 0 0;} .Footer .footer-links-wrap .col:nth-child(2), .Footer .footer-links-wrap .col:nth-child(3), .Footer .footer-links-wrap .col:nth-child(4) {border-bottom:1px solid #c4c4c4; border-right:none} a.dropdown-1-title, a.dropdown-2-title, a.dropdown-3-title {color: #8a8a8a; font-style: italic;} .signin-icon {display: none;} #signin .header-bottom-item.header-bottom-link {margin-top: -10px;} } @media screen and (min-width:992px){ .Hamburger, .dropdownnavi .top-header-link, #userguidesLink, #supportLink, .smdropdown-alt {display: none;} .bottom-header {display: block;} .header-top-link::after {background: #fff;} header .row:nth-child(2) {background-color:white; box-shadow: 0 3px 5px rgba(0,0,0,0.1);} .depth-1-list, .depth-2-list, .depth-3-list {list-style: none; margin: 0; padding-left: 0; box-shadow: 0 4px 4px rgba(0,0,0,.1);} .depth-1-item, .depth-2-item, .depth-3-item {padding-left:15px; border-bottom:1px solid #dfdfdf; position: relative;} .depth-1-item a, .depth-2-item a, .depth-3-item a {color: #1e1e1e;} .header-bottom-link::after {background: #0014a0;} .header-top-link.active::after, .header-top-link:hover::after, .header-bottom-link.active::after, .header-bottom-link:hover::after {bottom: 0; content: ""; display: block; height: 5px; left: -15px; margin: auto; position: absolute; width: calc(100% + 35px);} .header-bottom-link.smdropdown:hover, .header-bottom-link.smdropdown.active {color:#0014a0} .header-searchbox {position:absolute;top:0;right:60px; margin:0; z-index: 200; } .header-searchbox.active {width:500px;transition: 1s ease-in-out;} #kbsearch {width:350px;} #menu-dropdown, #kb-menu-dropdown {position: absolute; z-index: 100; background: white; text-align: left; margin: 1px 0 0 -15px;} #menu-dropdown, #kb-menu-dropdown .depth-1-list {width:280px} #kb-menu-dropdown .depth-2-list {width:350px!important} #profile-menu {position: absolute; z-index: 100; background: white; width: 350px; text-align: left; width:260px; margin: 0 0 0 -230px; border: 1px solid #c4c4c4; border-radius: 5px; box-shadow: 0 4px 4px rgba(0,0,0,.1);} #menu-dropdown, #menu-dropdown .depth-2-list, #menu-dropdown .depth-3-list, #kb-menu-dropdown, #kb-menu-dropdown .depth-2-list, #profile-menu {display:none;} #helpForumsLink:hover #menu-dropdown, #FaqsLink:hover #kb-menu-dropdown, #profiledropdown:hover #profile-menu {display: block;} #menu-dropdown .depth-1-item:hover .depth-2-list, #menu-dropdown .depth-2-item:hover .depth-3-list, #kb-menu-dropdown .depth-1-item:hover .depth-2-list { display: block; left: calc(100%); background: #fff; border: 1px solid #c4c4c4; position: absolute; top: 0; width: 100%;} #kb-menu-dropdown .depth-1-url {margin:0} #menu-dropdown .depth-1-item:nth-child(3) .depth-2-list, #menu-dropdown .depth-2-item:hover .depth-3-list {top:-1px} .depth-1-item:hover, .depth-2-item:hover, .depth-3-item:hover {pointer:cursor;background-color:#f8f8f8} #helpForumsLink .depth-1-item:hover .depth-1-url, .depth-2-item:hover .depth-2-url, .depth-3-item:hover .depth-3-url, #kb-menu-dropdown .depth-2-item:hover .depth-3-url {color:#0014a0} #FaqsLink .depth-1-item:hover, #FaqsLink .depth-1-item:hover .depth-1-url {cursor:default} .header-right {float: right; margin: 8px 15px 0 0; padding: 3px; height: 30px; border-radius: 3px;} #profiledropdown {padding: 2px; border-radius: 3px; margin-top: -3px;} #dropdownnavi {margin: -1px 0 0 -13px;} #dropdownnavi .top-header-link, .dropdown-1-title, .dropdown-2-title, .dropdown-3-title {display:none} .header-bottom-link.smdropdown {line-height:53px} #signin {display:flex; margin: 1px -12px 0 0} #signin .header-bottom-item.header-bottom-link {margin-top:-14px; height:54px} #signin span {margin-top: 3px;} .signin-icon {padding: 4px 0 20px 0;} .header-bottom-link.smdropdown:before {content:url("data:image/svg+xml;utf8,<svg version='1.1' xmlns='http://www.w3.org/2000/svg' xmlns:xlink='http://www.w3.org/1999/xlink' width='26px' height='18px' xml:space='preserve'><g><path fill='none' stroke='%23010101' stroke-width='2' stroke-linecap='round' stroke-linejoin='round' stroke-miterlimit='10' d='M13.014,14'/></g><g><path fill='%23010101' d='M13,16c-0.256,0-0.512-0.098-0.707-0.293l-3-3c-0.391-0.391-0.391-1.023,0-1.414s1.023-0.391,1.414,0L13,13.586l2.293-2.293c0.391-0.391,1.023-0.391,1.414,0s0.391,1.023,0,1.414l-3,3C13.512,15.902,13.256,16,13,16z'/> </g> </svg>")!important;float: right;} #helpForumsLink:hover .header-bottom-link.smdropdown::before, #FaqsLink:hover .header-bottom-link.smdropdown::before, .header-bottom-link.smdropdown:hover::before {content:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='26px' height='18px' fill='%23010101'><path d='M16,16c-0.256,0-0.512-0.098-0.707-0.293L13,13.414l-2.293,2.293c-0.391,0.391-1.023,0.391-1.414,0s-0.391-1.023,0-1.414l3-3c0.391-0.391,1.023-0.391,1.414,0l3,3c0.391,0.391,0.391,1.023,0,1.414C16.512,15.902,16.256,16,16,16z'/></svg>")!important;} .depth-1-item:before, #helpForumsLink .depth-2-item:before {content:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='26px' height='18px' fill='%23010101'><path d='M12,17c-0.256,0-0.512-0.098-0.707-0.293c-0.391-0.391-0.391-1.023,0-1.414L13.586,13l-2.293-2.293c-0.391-0.391-0.391-1.023,0-1.414s1.023-0.391,1.414,0l3,3c0.391,0.391,0.391,1.023,0,1.414l-3,3C12.512,16.902,12.256,17,12,17z'/></svg>");float:right;} .depth-1-item:hover::before, #helpForumsLink .depth-2-item:hover::before {content:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='26px' height='18px' fill='%23010101'><path d='M14,17c-0.256,0-0.512-0.098-0.707-0.293l-3-3c-0.391-0.391-0.391-1.023,0-1.414l3-3c0.391-0.391,1.023-0.391,1.414,0s0.391,1.023,0,1.414L12.414,13l2.293,2.293c0.391,0.391,0.391,1.023,0,1.414C14.512,16.902,14.256,17,14,17z'/></svg>")!important;} }

Understanding Neighborcast

This article gives a quick overview of the Neighborcast feature in the F-Secure Automatic Update Agent (AUA), and also provides detailed information on its download logic.

Neighborcast is configured via three options:

Neighborcast client (enabled/disabled) - controls whether the client tries to locate updates from clients in the same LAN.
Neighborcast server (enabled/disabled) - controls whether the client listens and responds to neighborcast queries and offers updates for download.
Neighborcast port - port used for neighborcast UDP queries.

When neighborcast is enabled, the client

gets a list of available updates from Policy Manager Server (PMS)/Automatic Update Server (AUS)
makes the decision to download an update
sends a neighborcast query via broadcast UDP packet over the configured neighborcast port
receives a unicast UDP reply back from other clients having the update
picks a suitable peer and sends it a unicast UDP 'open session'
after a positive confirmation, proceeds to download files over HTTP directly from the selected peer
after downloading all the files, terminates the neighborcast session
checks the received files against MD5 hashes and downloads any missing or corrupted files from PMS/AUS.