Update the default port for [ips] and [ips_fixed]:

If a port number is not specified in the [ips] or [ips_fixed]
blocks, automatically add the new default peer port which was
registered with IANA: 2459. Also use 2459 if no port is specified
with manually using the `connect` command; previously it was
using 6561, which could have resulted in spurious failures.
This commit, if merged, fixes #2861.

src/ripple/overlay/impl/OverlayImpl.cpp

@@ -554,13 +554,8 @@ OverlayImpl::onPrepare()
             for (auto const& addr : addresses)
             {
                 if (addr.port() == 0)
-                {
+                    ips.push_back(to_string(addr.at_port(DEFAULT_PEER_PORT)));
-                    Throw<std::runtime_error>(
+                else
-                        "Port not specified for "
-                        "address:" +
-                        addr.to_string());
-                }
-
                     ips.push_back(to_string(addr));
             }
 
@@ -577,8 +572,19 @@ OverlayImpl::onPrepare()
             [this](
                 std::string const& name,
                 std::vector<beast::IP::Endpoint> const& addresses) {
-                if (!addresses.empty())
+                std::vector<beast::IP::Endpoint> ips;
-                    m_peerFinder->addFixedPeer(name, addresses);
+                ips.reserve(addresses.size());
+
+                for (auto& addr : addresses)
+                {
+                    if (addr.port() == 0)
+                        ips.emplace_back(addr.address(), DEFAULT_PEER_PORT);
+                    else
+                        ips.emplace_back(addr);
+                }
+
+                if (!ips.empty())
+                    m_peerFinder->addFixedPeer(name, ips);
             });
     }
 }

src/ripple/protocol/SystemParameters.h

@@ -61,4 +61,7 @@ static std::uint32_t constexpr XRP_LEDGER_EARLIEST_SEQ{32570};
 
 }  // namespace ripple
 
+/** Default peer port (IANA registered) */
+inline std::uint16_t constexpr DEFAULT_PEER_PORT{2459};
+
 #endif

src/ripple/rpc/handlers/Connect.cpp

@@ -22,6 +22,7 @@
 #include <ripple/net/RPCErr.h>
 #include <ripple/overlay/Overlay.h>
 #include <ripple/protocol/ErrorCodes.h>
+#include <ripple/protocol/SystemParameters.h>
 #include <ripple/protocol/jss.h>
 #include <ripple/rpc/Context.h>
 #include <ripple/rpc/impl/Handler.h>
@@ -53,7 +54,7 @@ doConnect(RPC::JsonContext& context)
     if (context.params.isMember(jss::port))
         iPort = context.params[jss::port].asInt();
     else
-        iPort = 6561;
+        iPort = DEFAULT_PEER_PORT;
 
     auto ip =
         beast::IP::Endpoint::from_string(context.params[jss::ip].asString());